From indiajoe at gmail.com  Mon Sep  1 14:24:40 2014
From: indiajoe at gmail.com (Joe Philip Ninan)
Date: Mon, 1 Sep 2014 23:54:40 +0530
Subject: [AstroPy] how to flatten an optical spectrum of a star
In-Reply-To: <CABb23mujtFJg39N8OV4MLkcbyJ+qUVfEzNpboVOyoa0pwLWGmA@mail.gmail.com>
References: <CABb23mujtFJg39N8OV4MLkcbyJ+qUVfEzNpboVOyoa0pwLWGmA@mail.gmail.com>
Message-ID: <CAJ_T+b5drcuuj_zqHw-yA3ChAP1i2i8QRdKzP8-KWHdPcRJcDA@mail.gmail.com>

Hi Hang,
I am not sure, i understand exactly what you mean by flattened spectrum.
Are you talking about Continuum Normalised Spectrum?

If so, you can do it in python, by dividing the original spectrum with a
smooth curve, which is obtained by fitting the spectrum with a heavily
smoothed spline OR low order polynomial.
You can use scipy and numpy modules for it.
-cheers
joe



On 1 September 2014 08:39, gonghang.naoc <ghang.naoc at gmail.com> wrote:

> Hi all,
> Sometimes we can see a star's spectrum is flattened. That is because we
> have already known its black body continuum well and a flattened spectrum
> can save space, right?
>
> A naive question is generally how to make that kind of spectrum?  Every
> point is divided by its neighbours? values?
> Is there any ready made python module to do that?
>
> Thank you.
> hang
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>
>


-- 
/---------------------------------------------------------------
"GNU/Linux: because a PC is a terrible thing to waste" -  GNU Generation

************************************************
Joe Philip Ninan
Research Scholar        /________________\
DAA,                            | Vadakeparambil |
TIFR,                           | Pullad P.O.         |
Mumbai-05, India.      | Kerala, India      |
Ph: +917738438212   | PIN:689548       |
------------------------------\_______________/--------------
My GnuPG Public Key:
https://sites.google.com/site/jpninan/index-html/aboutmehtml/JPN_public.key?attredirects=0&d=1
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From ghang.naoc at gmail.com  Tue Sep  2 07:45:26 2014
From: ghang.naoc at gmail.com (gonghang.naoc)
Date: Tue, 2 Sep 2014 19:45:26 +0800
Subject: [AstroPy] how to flatten an optical spectrum of a star
In-Reply-To: <CAJ_T+b5drcuuj_zqHw-yA3ChAP1i2i8QRdKzP8-KWHdPcRJcDA@mail.gmail.com>
References: <CABb23mujtFJg39N8OV4MLkcbyJ+qUVfEzNpboVOyoa0pwLWGmA@mail.gmail.com>
	<CAJ_T+b5drcuuj_zqHw-yA3ChAP1i2i8QRdKzP8-KWHdPcRJcDA@mail.gmail.com>
Message-ID: <CABb23mvq3mvA7YdN3LxQYpcjh=4gSRgu6cj2WXzGW3ss-uWsFg@mail.gmail.com>

Thanks, Joe. Now I get it.
best
hang


On Tue, Sep 2, 2014 at 2:24 AM, Joe Philip Ninan <indiajoe at gmail.com> wrote:

> Hi Hang,
> I am not sure, i understand exactly what you mean by flattened spectrum.
> Are you talking about Continuum Normalised Spectrum?
>
> If so, you can do it in python, by dividing the original spectrum with a
> smooth curve, which is obtained by fitting the spectrum with a heavily
> smoothed spline OR low order polynomial.
> You can use scipy and numpy modules for it.
> -cheers
> joe
>
>
>
> On 1 September 2014 08:39, gonghang.naoc <ghang.naoc at gmail.com> wrote:
>
>> Hi all,
>> Sometimes we can see a star's spectrum is flattened. That is because we
>> have already known its black body continuum well and a flattened spectrum
>> can save space, right?
>>
>> A naive question is generally how to make that kind of spectrum?  Every
>> point is divided by its neighbours? values?
>> Is there any ready made python module to do that?
>>
>> Thank you.
>> hang
>>
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
>>
>>
>
>
> --
> /---------------------------------------------------------------
> "GNU/Linux: because a PC is a terrible thing to waste" -  GNU Generation
>
> ************************************************
> Joe Philip Ninan
> Research Scholar        /________________\
> DAA,                            | Vadakeparambil |
> TIFR,                           | Pullad P.O.         |
> Mumbai-05, India.      | Kerala, India      |
> Ph: +917738438212   | PIN:689548       |
> ------------------------------\_______________/--------------
> My GnuPG Public Key:
> https://sites.google.com/site/jpninan/index-html/aboutmehtml/JPN_public.key?attredirects=0&d=1
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>
>
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From p3y1i4n at gmail.com  Tue Sep  2 09:40:16 2014
From: p3y1i4n at gmail.com (Pey Lian Lim)
Date: Tue, 2 Sep 2014 09:40:16 -0400
Subject: [AstroPy] how to flatten an optical spectrum of a star
Message-ID: <CAJt49iQe8CrBcqdMT6=GvY=bS=ah_1irp7bCd6_4mvpfcg-9fw@mail.gmail.com>

Hi Hang,

You can probably do it with pysynphot (which is currently not a part
of astropy). It is currently distributed with
http://www.stsci.edu/institute/software_hardware/pyraf/stsci_python
but there are long-term plans to port it to astropy and use modeling.

I tried the following and I could recover the Gaussian emission line
by subtracting away the blackbody spectrum that I added at the
beginning:

>>> import pysynphot as S
>>> bb = S.BlackBody(5000)
>>> gg = S.GaussianSource(0.03, 4500, 100, fluxunits='photlam')
>>> source_with_bg = bb + gg
>>> source_no_bg = source_with_bg - bb

If you have questions about pysynphot, please contact help[at]stsci.edu .

Hope this helps,
Pey-Lian


From ghang.naoc at gmail.com  Thu Sep  4 07:59:06 2014
From: ghang.naoc at gmail.com (gonghang.naoc)
Date: Thu, 4 Sep 2014 19:59:06 +0800
Subject: [AstroPy] time conversion between JD and UT
Message-ID: <CABb23msTR3NavcPQT+iqwp012HcMzxnsdQmWz9Kj6udRbzvARw@mail.gmail.com>

Hi all,
I am trying astropy.time to do conversion between JD and UT.
It is easier to convert UT to JD.  It seems JD equals jd1+jd2, right?  I do
not know why there are two parts since one value is enough.
However It is difficult to convert JD to UT? It seems there is no relative
manipulation in this package.

>>> from astropy.time import Time
>>> t = Time('2010-01-01 00:00:00', scale='utc')>>> t.jd1, t.jd2(2455197.5, 0.0)

best
Thank you.
hang
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From tim.jenness at gmail.com  Thu Sep  4 10:54:55 2014
From: tim.jenness at gmail.com (Tim Jenness)
Date: Thu, 4 Sep 2014 07:54:55 -0700
Subject: [AstroPy] time conversion between JD and UT
In-Reply-To: <CABb23msTR3NavcPQT+iqwp012HcMzxnsdQmWz9Kj6udRbzvARw@mail.gmail.com>
References: <CABb23msTR3NavcPQT+iqwp012HcMzxnsdQmWz9Kj6udRbzvARw@mail.gmail.com>
Message-ID: <CA+G92Rc_HJVe76efHNGOp4rdWpWMzjdSBRjPZjRnKgaPX7vVyw@mail.gmail.com>

On Thu, Sep 4, 2014 at 4:59 AM, gonghang.naoc <ghang.naoc at gmail.com> wrote:

> Hi all,
> I am trying astropy.time to do conversion between JD and UT.
> It is easier to convert UT to JD.  It seems JD equals jd1+jd2, right?  I
> do not know why there are two parts since one value is enough.
>

There are two values to allow you use high precision. A single double
precision number can not provide you with nanosecond precision as a JD. If
you split the JD into two distinct numbers (apportioned in a way that best
suits your requirements) you can retain accuracy.

-- 
Tim Jenness
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From ghang.naoc at gmail.com  Thu Sep  4 11:01:44 2014
From: ghang.naoc at gmail.com (gonghang.naoc)
Date: Thu, 4 Sep 2014 23:01:44 +0800
Subject: [AstroPy] time conversion between JD and UT
In-Reply-To: <CA+G92Rc_HJVe76efHNGOp4rdWpWMzjdSBRjPZjRnKgaPX7vVyw@mail.gmail.com>
References: <CABb23msTR3NavcPQT+iqwp012HcMzxnsdQmWz9Kj6udRbzvARw@mail.gmail.com>
	<CA+G92Rc_HJVe76efHNGOp4rdWpWMzjdSBRjPZjRnKgaPX7vVyw@mail.gmail.com>
Message-ID: <CABb23ms7hRh8kuVe6mBWozS3y1pF9pzXeY846jspcAHtd5WhKw@mail.gmail.com>

You mean jd2 is very small? It can be as large as,say, 0.3.



On Thu, Sep 4, 2014 at 10:54 PM, Tim Jenness <tim.jenness at gmail.com> wrote:

>
>
>
> On Thu, Sep 4, 2014 at 4:59 AM, gonghang.naoc <ghang.naoc at gmail.com>
> wrote:
>
>> Hi all,
>> I am trying astropy.time to do conversion between JD and UT.
>> It is easier to convert UT to JD.  It seems JD equals jd1+jd2, right?  I
>> do not know why there are two parts since one value is enough.
>>
>
> There are two values to allow you use high precision. A single double
> precision number can not provide you with nanosecond precision as a JD. If
> you split the JD into two distinct numbers (apportioned in a way that best
> suits your requirements) you can retain accuracy.
>
> --
> Tim Jenness
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>
>
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From aldcroft at head.cfa.harvard.edu  Thu Sep  4 11:08:24 2014
From: aldcroft at head.cfa.harvard.edu (Aldcroft, Thomas)
Date: Thu, 4 Sep 2014 11:08:24 -0400
Subject: [AstroPy] time conversion between JD and UT
In-Reply-To: <CABb23msTR3NavcPQT+iqwp012HcMzxnsdQmWz9Kj6udRbzvARw@mail.gmail.com>
References: <CABb23msTR3NavcPQT+iqwp012HcMzxnsdQmWz9Kj6udRbzvARw@mail.gmail.com>
Message-ID: <CAMtEP6z4_2VvXSED2fTm1AjzjiohwwfkY1H8=oMitCYLA-0raw@mail.gmail.com>

On Thu, Sep 4, 2014 at 7:59 AM, gonghang.naoc <ghang.naoc at gmail.com> wrote:

> Hi all,
> I am trying astropy.time to do conversion between JD and UT.
> It is easier to convert UT to JD.  It seems JD equals jd1+jd2, right?  I
> do not know why there are two parts since one value is enough.
> However It is difficult to convert JD to UT? It seems there is no relative
> manipulation in this package.
>
> >>> from astropy.time import Time
> >>> t = Time('2010-01-01 00:00:00', scale='utc')>>> t.jd1, t.jd2(2455197.5, 0.0)
>
> Hi Hang,

This is probably what you want:

>>> from astropy.time import Time
>>> t = Time('2010-01-01 00:00:00', scale='utc')
>>> t
<Time object: scale='utc' format='iso' value=2010-01-01 00:00:00.000>
>>> t.jd
2455197.5
>>> t_jd = Time(2455197.5, format='jd', scale='utc')
>>> t_jd
<Time object: scale='utc' format='jd' value=2455197.5>
>>> t_jd.iso
'2010-01-01 00:00:00.000'

All of this should be covered in the documentation (
http://astropy.readthedocs.org/en/stable/time/index.html) so you might want
to take a few minutes to read that through.

Cheers,
Tom

>
> best
> Thank you.
> hang
>
>
>
>
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>
>
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From ghang.naoc at gmail.com  Thu Sep  4 11:25:05 2014
From: ghang.naoc at gmail.com (gonghang.naoc)
Date: Thu, 4 Sep 2014 23:25:05 +0800
Subject: [AstroPy] time conversion between JD and UT
In-Reply-To: <CAMtEP6z4_2VvXSED2fTm1AjzjiohwwfkY1H8=oMitCYLA-0raw@mail.gmail.com>
References: <CABb23msTR3NavcPQT+iqwp012HcMzxnsdQmWz9Kj6udRbzvARw@mail.gmail.com>
	<CAMtEP6z4_2VvXSED2fTm1AjzjiohwwfkY1H8=oMitCYLA-0raw@mail.gmail.com>
Message-ID: <CABb23mtvjaO+mTyFyCLToATpa5pu_VrjDb4DbpDogMmDMmnkhA@mail.gmail.com>

Oh, that works.Thank you very much.
best
hang


On Thu, Sep 4, 2014 at 11:08 PM, Aldcroft, Thomas <
aldcroft at head.cfa.harvard.edu> wrote:

>
>
>
> On Thu, Sep 4, 2014 at 7:59 AM, gonghang.naoc <ghang.naoc at gmail.com>
> wrote:
>
>> Hi all,
>> I am trying astropy.time to do conversion between JD and UT.
>> It is easier to convert UT to JD.  It seems JD equals jd1+jd2, right?  I
>> do not know why there are two parts since one value is enough.
>> However It is difficult to convert JD to UT? It seems there is no
>> relative manipulation in this package.
>>
>> >>> from astropy.time import Time
>> >>> t = Time('2010-01-01 00:00:00', scale='utc')>>> t.jd1, t.jd2(2455197.5, 0.0)
>>
>> Hi Hang,
>
> This is probably what you want:
>
> >>> from astropy.time import Time
> >>> t = Time('2010-01-01 00:00:00', scale='utc')
> >>> t
> <Time object: scale='utc' format='iso' value=2010-01-01 00:00:00.000>
> >>> t.jd
> 2455197.5
> >>> t_jd = Time(2455197.5, format='jd', scale='utc')
> >>> t_jd
> <Time object: scale='utc' format='jd' value=2455197.5>
> >>> t_jd.iso
> '2010-01-01 00:00:00.000'
>
> All of this should be covered in the documentation (
> http://astropy.readthedocs.org/en/stable/time/index.html) so you might
> want to take a few minutes to read that through.
>
> Cheers,
> Tom
>
>>
>> best
>> Thank you.
>> hang
>>
>>
>>
>>
>>
>>
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
>>
>>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>
>
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From npkuin at gmail.com  Thu Sep  4 21:24:45 2014
From: npkuin at gmail.com (Paul Kuin)
Date: Fri, 5 Sep 2014 02:24:45 +0100
Subject: [AstroPy] issue with initialisation of a fits binary table
Message-ID: <CANoQ6N26k0DKMPRJrepHBw94XZf9feq3n-swKECkbWfxZ0YsRw@mail.gmail.com>

Hi,

I have a question about io.fits

I wonder if I just miss something obvious, or it can only be done as a
later fix. Let me explain my problem.

When adding a card to the header, I can do that as

header["NEW_KEY"]=("SOME_VALUE","this is an example")
and in the header I get
NEW_KEY = "SOME_VALUE"   \ this is an example

So with a keyword.

Now, when I define a new column like

col = [fits.Column(name="Vmag",format="E",unit="mag",ascii=False)]
I can create a binary table
tab = fits.BinTableHDU.from_columns(columns=col)

The header then is created with a TTYPE keyword with a value, but without a
comment.
Comments are sometimes very useful, and so I checked.

I can define
col = [fits.Column(name=("Vmag","some
comment"),format="E",unit="mag",ascii=False)]
which goes some way to being able to have a TTYPE keyword with value and
comment,
but then trying to create the binary table HDU as before, it fails.

Am I missing something?

I can probably go back in and modify the header to add comments once I have
the bintable HDU defined, but it seems so inelegant I did not even try.


    Paul

-- 

* * * * * * * * http://www.mssl.ucl.ac.uk/~npmk/ * * * *
Dr. N.P.M. Kuin      (n.kuin at ucl.ac.uk)
phone +44-(0)1483 (prefix) -204927 (work)
mobile +44(0)7806985366  skype ID: npkuin
Mullard Space Science Laboratory  ? University College London  ?
Holmbury St Mary ? Dorking ? Surrey RH5 6NT?  U.K.
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From embray at stsci.edu  Mon Sep  8 09:59:54 2014
From: embray at stsci.edu (Erik Bray)
Date: Mon, 8 Sep 2014 09:59:54 -0400
Subject: [AstroPy] issue with initialisation of a fits binary table
In-Reply-To: <CANoQ6N26k0DKMPRJrepHBw94XZf9feq3n-swKECkbWfxZ0YsRw@mail.gmail.com>
References: <CANoQ6N26k0DKMPRJrepHBw94XZf9feq3n-swKECkbWfxZ0YsRw@mail.gmail.com>
Message-ID: <540DB65A.3020201@stsci.edu>

On 09/04/2014 09:24 PM, Paul Kuin wrote:
> Hi,
>
> I have a question about io.fits
>
> I wonder if I just miss something obvious, or it can only be done as a later
> fix. Let me explain my problem.
>
> When adding a card to the header, I can do that as
>
> header["NEW_KEY"]=("SOME_VALUE","this is an example")
> and in the header I get
> NEW_KEY = "SOME_VALUE"   \ this is an example
>
> So with a keyword.
>
> Now, when I define a new column like
>
> col = [fits.Column(name="Vmag",format="E",unit="mag",ascii=False)]
> I can create a binary table
> tab = fits.BinTableHDU.from_columns(columns=col)
>
> The header then is created with a TTYPE keyword with a value, but without a comment.
> Comments are sometimes very useful, and so I checked.
>
> I can define
> col = [fits.Column(name=("Vmag","some comment"),format="E",unit="mag",ascii=False)]
> which goes some way to being able to have a TTYPE keyword with value and comment,
> but then trying to create the binary table HDU as before, it fails.
>
> Am I missing something?
>
> I can probably go back in and modify the header to add comments once I have the
> bintable HDU defined, but it seems so inelegant I did not even try.

Just set

header.comments['TTYPE'] = 'Whatever'

after the fact.  Indeed, comments are nice to have, but they're mostly 
orthogonal to the actual structure of FITS files which we're trying to abstract 
away as much as possible.

If/when the FITS Schema infrastructure I've been working on is ready and 
integrated it will also be possible to define local schemas that provide 
standard comments to various header keywords, but that's a ways off.

As an aside, it's not necessary here to specify `ascii=False` in the Column() 
initialization.  That's already the default, and is only needed to create 
columns for ASCII tables when there's some ambiguity in the format code.

Erik



From garyb at physics.upenn.edu  Mon Sep  8 10:40:05 2014
From: garyb at physics.upenn.edu (Gary Bernstein)
Date: Mon, 8 Sep 2014 10:40:05 -0400
Subject: [AstroPy] Read FITS headers without loading data
Message-ID: <C531948D-B0B2-4331-A359-E5646D59BA63@physics.upenn.edu>

I would like to extract the header information from a large multi-extension FITS file using astropy.io.fits.  This runs very slowly, and I suspect because it is reading the data of each extension when the header is accessed e.g. via

import astropy.io.fits as pf
f = pf.open(?mef.fits?)
for hdu in f:
    h = hdu.header
    ? do stuff with header?

It is *much* faster using e.g. cfitsio utilities (<<1 second compared to 10?s of seconds for the above on a multiple-GB file).  Am I correct that the data is being loaded for each extension in the above method?  If so is there a workaround?  Neither using getheader nor (un)setting memmap seems to make a difference.


Thanks,
Gary Bernstein




From npkuin at gmail.com  Mon Sep  8 11:14:26 2014
From: npkuin at gmail.com (Paul Kuin)
Date: Mon, 8 Sep 2014 16:14:26 +0100
Subject: [AstroPy] issue with initialisation of a fits binary table
In-Reply-To: <540DB65A.3020201@stsci.edu>
References: <CANoQ6N26k0DKMPRJrepHBw94XZf9feq3n-swKECkbWfxZ0YsRw@mail.gmail.com>
	<540DB65A.3020201@stsci.edu>
Message-ID: <CANoQ6N0y2LVtKKzCQ6DknvJfn2v_+ckgNq97aGPnHoTj-bYfOg@mail.gmail.com>

Hi Erik,

The problem I see with that is that I won't know in advance which keyword
is TTYPE1, TTYPE2, etc. although it probably is in sequence. At the moment
I just will let it be. Good to know you are working on improving that for
the new version.

One other item that really bugged me later was trying to add a row to a
binTable.There's no good way to do that. I wrote a work-around. I suppose
that will also be fixed in the next release.

Cheers,

   Paul

On Mon, Sep 8, 2014 at 2:59 PM, Erik Bray <embray at stsci.edu> wrote:

> On 09/04/2014 09:24 PM, Paul Kuin wrote:
> > Hi,
> >
> > I have a question about io.fits
> >
> > I wonder if I just miss something obvious, or it can only be done as a
> later
> > fix. Let me explain my problem.
> >
> > When adding a card to the header, I can do that as
> >
> > header["NEW_KEY"]=("SOME_VALUE","this is an example")
> > and in the header I get
> > NEW_KEY = "SOME_VALUE"   \ this is an example
> >
> > So with a keyword.
> >
> > Now, when I define a new column like
> >
> > col = [fits.Column(name="Vmag",format="E",unit="mag",ascii=False)]
> > I can create a binary table
> > tab = fits.BinTableHDU.from_columns(columns=col)
> >
> > The header then is created with a TTYPE keyword with a value, but
> without a comment.
> > Comments are sometimes very useful, and so I checked.
> >
> > I can define
> > col = [fits.Column(name=("Vmag","some
> comment"),format="E",unit="mag",ascii=False)]
> > which goes some way to being able to have a TTYPE keyword with value and
> comment,
> > but then trying to create the binary table HDU as before, it fails.
> >
> > Am I missing something?
> >
> > I can probably go back in and modify the header to add comments once I
> have the
> > bintable HDU defined, but it seems so inelegant I did not even try.
>
> Just set
>
> header.comments['TTYPE'] = 'Whatever'
>
> after the fact.  Indeed, comments are nice to have, but they're mostly
> orthogonal to the actual structure of FITS files which we're trying to
> abstract
> away as much as possible.
>
> If/when the FITS Schema infrastructure I've been working on is ready and
> integrated it will also be possible to define local schemas that provide
> standard comments to various header keywords, but that's a ways off.
>
> As an aside, it's not necessary here to specify `ascii=False` in the
> Column()
> initialization.  That's already the default, and is only needed to create
> columns for ASCII tables when there's some ambiguity in the format code.
>
> Erik
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>



-- 

* * * * * * * * http://www.mssl.ucl.ac.uk/~npmk/ * * * *
Dr. N.P.M. Kuin      (n.kuin at ucl.ac.uk)
phone +44-(0)1483 (prefix) -204927 (work)
mobile +44(0)7806985366  skype ID: npkuin
Mullard Space Science Laboratory  ? University College London  ?
Holmbury St Mary ? Dorking ? Surrey RH5 6NT?  U.K.
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From embray at stsci.edu  Mon Sep  8 11:14:25 2014
From: embray at stsci.edu (Erik Bray)
Date: Mon, 8 Sep 2014 11:14:25 -0400
Subject: [AstroPy] Read FITS headers without loading data
In-Reply-To: <C531948D-B0B2-4331-A359-E5646D59BA63@physics.upenn.edu>
References: <C531948D-B0B2-4331-A359-E5646D59BA63@physics.upenn.edu>
Message-ID: <540DC7D1.1020306@stsci.edu>

On 09/08/2014 10:40 AM, Gary Bernstein wrote:
> I would like to extract the header information from a large multi-extension FITS file using astropy.io.fits.  This runs very slowly, and I suspect because it is reading the data of each extension when the header is accessed e.g. via
>
> import astropy.io.fits as pf
> f = pf.open(?mef.fits?)
> for hdu in f:
>      h = hdu.header
>      ? do stuff with header?
>
> It is *much* faster using e.g. cfitsio utilities (<<1 second compared to 10?s of seconds for the above on a multiple-GB file).  Am I correct that the data is being loaded for each extension in the above method?  If so is there a workaround?  Neither using getheader nor (un)setting memmap seems to make a difference.

No, it doesn't touch the data when just reading headers.  The difference depends 
largely on what you're doing with the headers, though in general it's due to the 
fact that CFITSIO is written in C while PyFITS is written in pure Python, and 
does a lot more to parse headers into an in-memory data structure.

That said, how many headers are in this file?  It shouldn't take "10's of 
seconds" though again that might depend in part on what you're doing.

Erik



From thomas.robitaille at gmail.com  Mon Sep  8 11:18:20 2014
From: thomas.robitaille at gmail.com (Thomas Robitaille)
Date: Mon, 08 Sep 2014 17:18:20 +0200
Subject: [AstroPy] issue with initialisation of a fits binary table
In-Reply-To: <CANoQ6N0y2LVtKKzCQ6DknvJfn2v_+ckgNq97aGPnHoTj-bYfOg@mail.gmail.com>
References: <CANoQ6N26k0DKMPRJrepHBw94XZf9feq3n-swKECkbWfxZ0YsRw@mail.gmail.com>
	<540DB65A.3020201@stsci.edu>
	<CANoQ6N0y2LVtKKzCQ6DknvJfn2v_+ckgNq97aGPnHoTj-bYfOg@mail.gmail.com>
Message-ID: <540DC8BC.7000705@gmail.com>

Hi Paul,

To add a row, you could consider using the Table interface:

from astropy.table import Table
t = Table.read('thefile.fits')
t.add_row(...)
t.write('newfile.fits', overwrite=True)

and similarly to add a column. Generally speaking if you want to
manipulate the table you are much better off reading it in via the Table
interface.

Cheers,
Tom

Paul Kuin wrote:
> Hi Erik, 
> 
> The problem I see with that is that I won't know in advance which
> keyword is TTYPE1, TTYPE2, etc. although it probably is in sequence. At
> the moment I just will let it be. Good to know you are working on
> improving that for the new version. 
> 
> One other item that really bugged me later was trying to add a row to a
> binTable.There's no good way to do that. I wrote a work-around. I
> suppose that will also be fixed in the next release. 
> 
> Cheers, 
> 
>    Paul
> 
> On Mon, Sep 8, 2014 at 2:59 PM, Erik Bray <embray at stsci.edu
> <mailto:embray at stsci.edu>> wrote:
> 
>     On 09/04/2014 09:24 PM, Paul Kuin wrote:
>     > Hi,
>     >
>     > I have a question about io.fits
>     >
>     > I wonder if I just miss something obvious, or it can only be done
>     as a later
>     > fix. Let me explain my problem.
>     >
>     > When adding a card to the header, I can do that as
>     >
>     > header["NEW_KEY"]=("SOME_VALUE","this is an example")
>     > and in the header I get
>     > NEW_KEY = "SOME_VALUE"   \ this is an example
>     >
>     > So with a keyword.
>     >
>     > Now, when I define a new column like
>     >
>     > col = [fits.Column(name="Vmag",format="E",unit="mag",ascii=False)]
>     > I can create a binary table
>     > tab = fits.BinTableHDU.from_columns(columns=col)
>     >
>     > The header then is created with a TTYPE keyword with a value, but
>     without a comment.
>     > Comments are sometimes very useful, and so I checked.
>     >
>     > I can define
>     > col = [fits.Column(name=("Vmag","some
>     comment"),format="E",unit="mag",ascii=False)]
>     > which goes some way to being able to have a TTYPE keyword with
>     value and comment,
>     > but then trying to create the binary table HDU as before, it fails.
>     >
>     > Am I missing something?
>     >
>     > I can probably go back in and modify the header to add comments
>     once I have the
>     > bintable HDU defined, but it seems so inelegant I did not even try.
> 
>     Just set
> 
>     header.comments['TTYPE'] = 'Whatever'
> 
>     after the fact.  Indeed, comments are nice to have, but they're mostly
>     orthogonal to the actual structure of FITS files which we're trying
>     to abstract
>     away as much as possible.
> 
>     If/when the FITS Schema infrastructure I've been working on is ready and
>     integrated it will also be possible to define local schemas that provide
>     standard comments to various header keywords, but that's a ways off.
> 
>     As an aside, it's not necessary here to specify `ascii=False` in the
>     Column()
>     initialization.  That's already the default, and is only needed to
>     create
>     columns for ASCII tables when there's some ambiguity in the format code.
> 
>     Erik
> 
>     _______________________________________________
>     AstroPy mailing list
>     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     http://mail.scipy.org/mailman/listinfo/astropy
> 
> 
> 
> 
> -- 
> 
> * * * * * * * * http://www.mssl.ucl.ac.uk/~npmk/ * * * *
> Dr. N.P.M. Kuin      (n.kuin at ucl.ac.uk <mailto:n.kuin at ucl.ac.uk>)      
> phone +44-(0)1483 (prefix) -204927 (work)
> mobile +44(0)7806985366  skype ID: npkuin
> Mullard Space Science Laboratory  ? University College London  ?
> Holmbury St Mary ? Dorking ? Surrey RH5 6NT?  U.K.
> 
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy


From garyb at physics.upenn.edu  Mon Sep  8 11:58:12 2014
From: garyb at physics.upenn.edu (Gary Bernstein)
Date: Mon, 8 Sep 2014 11:58:12 -0400
Subject: [AstroPy] Read FITS headers without loading data
In-Reply-To: <540DC7D1.1020306@stsci.edu>
References: <C531948D-B0B2-4331-A359-E5646D59BA63@physics.upenn.edu>
	<540DC7D1.1020306@stsci.edu>
Message-ID: <E2D55B6A-D55A-48FD-9B6F-8B4862AFCACE@physics.upenn.edu>

Thanks for setting me straight Erik.

Typically 60 extensions per FITS files.  Each is a binary table of cataloged objects from one CCD of a mosaic camera.  So there are many keywords in the header and perhaps I am just seeing the processing time for this.

On Sep 8, 2014, at 11:14 AM, Erik Bray <embray at stsci.edu> wrote:

> On 09/08/2014 10:40 AM, Gary Bernstein wrote:
>> I would like to extract the header information from a large multi-extension FITS file using astropy.io.fits.  This runs very slowly, and I suspect because it is reading the data of each extension when the header is accessed e.g. via
>> 
>> import astropy.io.fits as pf
>> f = pf.open(?mef.fits?)
>> for hdu in f:
>>     h = hdu.header
>>     ? do stuff with header?
>> 
>> It is *much* faster using e.g. cfitsio utilities (<<1 second compared to 10?s of seconds for the above on a multiple-GB file).  Am I correct that the data is being loaded for each extension in the above method?  If so is there a workaround?  Neither using getheader nor (un)setting memmap seems to make a difference.
> 
> No, it doesn't touch the data when just reading headers.  The difference depends 
> largely on what you're doing with the headers, though in general it's due to the 
> fact that CFITSIO is written in C while PyFITS is written in pure Python, and 
> does a lot more to parse headers into an in-memory data structure.
> 
> That said, how many headers are in this file?  It shouldn't take "10's of 
> seconds" though again that might depend in part on what you're doing.
> 
> Erik
> 
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
> 



From embray at stsci.edu  Mon Sep  8 12:21:08 2014
From: embray at stsci.edu (Erik Bray)
Date: Mon, 8 Sep 2014 12:21:08 -0400
Subject: [AstroPy] Read FITS headers without loading data
In-Reply-To: <E2D55B6A-D55A-48FD-9B6F-8B4862AFCACE@physics.upenn.edu>
References: <C531948D-B0B2-4331-A359-E5646D59BA63@physics.upenn.edu>	<540DC7D1.1020306@stsci.edu>
	<E2D55B6A-D55A-48FD-9B6F-8B4862AFCACE@physics.upenn.edu>
Message-ID: <540DD774.5070103@stsci.edu>

On 09/08/2014 11:58 AM, Gary Bernstein wrote:
> Thanks for setting me straight Erik.
>
> Typically 60 extensions per FITS files.  Each is a binary table of cataloged objects from one CCD of a mosaic camera.  So there are many keywords in the header and perhaps I am just seeing the processing time for this.

Thanks for clarifying-- indeed 60 headers each with many keywords is going to 
have an impact.  One way in which CFITSIO is different is that it does not 
actually parse the entire header at once, in general.  Instead when you request 
a particular keyword, for example, it will seek around until it finds it.

Generally very fast, but not appropriate for the richer data structures PyFITS 
provides where parsing much of the header in advance is necessary (though 
there's still a lot of shortcuts and lazy loading going on there too).

Actually if you wouldn't mind sending me a sample file that could be very 
helpful.  I don't have time to work on it right now, but "out of the ordinary" 
files like that are often very helpful for tracking down areas where performance 
can be improved.

Thanks,

Erik

> On Sep 8, 2014, at 11:14 AM, Erik Bray <embray at stsci.edu> wrote:
>
>> On 09/08/2014 10:40 AM, Gary Bernstein wrote:
>>> I would like to extract the header information from a large multi-extension FITS file using astropy.io.fits.  This runs very slowly, and I suspect because it is reading the data of each extension when the header is accessed e.g. via
>>>
>>> import astropy.io.fits as pf
>>> f = pf.open(?mef.fits?)
>>> for hdu in f:
>>>      h = hdu.header
>>>      ? do stuff with header?
>>>
>>> It is *much* faster using e.g. cfitsio utilities (<<1 second compared to 10?s of seconds for the above on a multiple-GB file).  Am I correct that the data is being loaded for each extension in the above method?  If so is there a workaround?  Neither using getheader nor (un)setting memmap seems to make a difference.
>>
>> No, it doesn't touch the data when just reading headers.  The difference depends
>> largely on what you're doing with the headers, though in general it's due to the
>> fact that CFITSIO is written in C while PyFITS is written in pure Python, and
>> does a lot more to parse headers into an in-memory data structure.
>>
>> That said, how many headers are in this file?  It shouldn't take "10's of
>> seconds" though again that might depend in part on what you're doing.
>>
>> Erik
>>
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
>>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>



From lsinger at caltech.edu  Mon Sep  8 21:48:25 2014
From: lsinger at caltech.edu (Leo Singer)
Date: Mon, 8 Sep 2014 18:48:25 -0700
Subject: [AstroPy] Astroquery module for Palomar Transient Factory data
	release?
Message-ID: <57590F52-B063-4018-B0B2-F6DE6C86F661@caltech.edu>

Hi,

This is a question about contributing some code to Astroquery to interact with the Palomar Transient Factory data release. I have some code that talks to IRSA's image server, which is currently used by WISE and PTF. The program interface is called IBE (not sure what it stands for). It supports cone searches and limited SQL-like queries to find images and catalog files for individual exposures. The system is described here:

http://www.ptf.caltech.edu/page/ibe

This is different from the existing astroquery.irsa module: that talks to a service called 'Gator' which provides access to catalogs; IBE, on the other hand, is designed for discovering data associated with given observations.

I would like to clean up my code and contribute it to Astroquery. Would this be better off as a new top-level package (astoquery.ibe), or as a new class inside astroquery.irsa?

Thanks,
Leo Singer
Graduate Student @ LIGO-Caltech


From asishrocks95 at gmail.com  Mon Sep 15 15:09:29 2014
From: asishrocks95 at gmail.com (Asish Panda)
Date: Mon, 15 Sep 2014 19:09:29 +0000 (UTC)
Subject: [AstroPy] I'd like to add you to my professional network on LinkedIn
Message-ID: <408132086.10370486.1410808169047.JavaMail.app@ela4-app8195.prod>

Hi astropy,

I&#39;d like to add you to my professional network on LinkedIn.

- Asish

Accept: http://www.linkedin.com/blink?simpleRedirect=38Pd30Ve3cQcjwOczwRcPsNejkZh4BKrSBQonhFtCVF9C9Du6RvoTd3fnBBiShBsC5EsOpQsSlRpRZBt6BSrCAZqSkConhzbmlQqnpKqiRQsSlRpORIrmkZpSVFqSdxsDgCpnhFtCV9pSlipn9Mfm4CsP8JcmhRsjoQc6AJsThGdCFKbjRBfP9SbSkLrmZzbCVFp6lHrCBIbDtTtOYLeDdMt7hE&msgID=I7893377690_1&markAsRead=


You received an invitation to connect. LinkedIn will use your email address to make suggestions to our members in features like People You May Know. Unsubscribe here: http://www.linkedin.com/blink?simpleRedirect=6tOrQkO9nBMqmdPc3gBun1LsDhPojRIqm5JpipQs64MczxGcTdSpP9IcDoZp6Bx9z4Sc30OfmhF9z4JfmhFripPcyQNp7lNdzgMqiRPt6ESqCUJfmhFpipQsSlRpRZBt6BSrCAZqSkCkjoPp4l7q5p6sCR6kk4ZrClHrRhAqmQCsSVRfngCsP8JcmhRsjoQc6AJsThGdCFKbjRBfP9SbSkLrmZzbCVFp6lHrCBIbDtTtOYLeDdMt7hE&amp;msgID=I7893377690_1&amp;markAsRead=This email was intended for astropy list. Learn why we included this at the following link: http://www.linkedin.com/blink?simpleRedirect=e3wTd3RAimlIoSBQsC4Ct7dBtmtvpnhFtCVFfmJB9CNOlmlzqnpOpldOpmRLt7dRoPRx9DcObj5Atn4Sd31FbndQqzpGryQZpjYOtyZBbSRLoOVKqmhBqSVFr2VTtTsLbPFMt7hE&msgID=I7893377690_1&markAsRead=
&copy; 2014, LinkedIn Corporation. 2029 Stierlin Ct. Mountain View, CA 94043, USA
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From udaraabeysekara at yahoo.com  Mon Sep 15 16:42:55 2014
From: udaraabeysekara at yahoo.com (Udara Abeysekara)
Date: Mon, 15 Sep 2014 13:42:55 -0700
Subject: [AstroPy] healpix_to_image
Message-ID: <1410813775.70901.YahooMailNeo@web126003.mail.ne1.yahoo.com>

Dear Astropy users

I am trying to convert a healpix map to a regular image fits 
file using healpix_to_image. I have a healpix map without the key word 
COORDSYS in the header. However, my understanding is healpix_to_image 
requires the key word COORDSYS. Does any one know a work arroung? Or is there a way that I can add the COORDSYS key word to my existing healpix map.

Early thanks for your time

Regards
Udara
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From maik.riechert at arcor.de  Tue Sep 16 15:44:29 2014
From: maik.riechert at arcor.de (Maik Riechert)
Date: Tue, 16 Sep 2014 21:44:29 +0200
Subject: [AstroPy] Plot constellations over image with WCS
Message-ID: <5418931D.6050601@arcor.de>

Hi,

Google didn't help me a lot so I thought this list is the best place for
my question.

What I'm after is drawing constellations over images with WCS info like
here:

http://nova.astrometry.net/user_images/401363#annotated
http://nova.astrometry.net/user_images/401685#annotated

Is there a Python package that does that? Of not, is there some kind of
online catalog (using astroquery?) for constellations that I could use?
A static small offline catalog would be fine too.

Thanks for suggestions,
Maik


From mperrin at stsci.edu  Tue Sep 16 15:54:27 2014
From: mperrin at stsci.edu (Marshall Perrin)
Date: Tue, 16 Sep 2014 19:54:27 +0000
Subject: [AstroPy] Plot constellations over image with WCS
In-Reply-To: <5418931D.6050601@arcor.de>
References: <5418931D.6050601@arcor.de>
Message-ID: <A1EC8E0B03630149876AA55EEE18C05C5BC5C08F@EXCHMAIL2.stsci.edu>

Hi Maik, 


See https://github.com/mperrin/misc_astro/blob/master/constellations.py

This supports both 2D plots like the ones you indicated, and 3D plots using mpl3d for rotating celestial sphere visualizations. 

The code is about 3 years old and I haven't tried it with any of the latest WCS visualization tools, but I'd imagine there won't be too many compatibility hurdles. Right now this just expects an Axes instance configured in degrees, and doesn't know anything directly about WCS or astropy coordinates, but it's got all the constellation outlines you're looking for. 

Hope this helps, 

 - Marshall



________________________________________
From: astropy-bounces at scipy.org [astropy-bounces at scipy.org] on behalf of Maik Riechert [maik.riechert at arcor.de]
Sent: Tuesday, September 16, 2014 3:44 PM
To: Astronomical Python mailing list
Subject: [AstroPy] Plot constellations over image with WCS

Hi,

Google didn't help me a lot so I thought this list is the best place for
my question.

What I'm after is drawing constellations over images with WCS info like
here:

http://nova.astrometry.net/user_images/401363#annotated
http://nova.astrometry.net/user_images/401685#annotated

Is there a Python package that does that? Of not, is there some kind of
online catalog (using astroquery?) for constellations that I could use?
A static small offline catalog would be fine too.

Thanks for suggestions,
Maik
_______________________________________________
AstroPy mailing list
AstroPy at scipy.org
http://mail.scipy.org/mailman/listinfo/astropy


From aycha.tammour at gmail.com  Wed Sep 17 10:12:38 2014
From: aycha.tammour at gmail.com (Aycha Tammour)
Date: Wed, 17 Sep 2014 10:12:38 -0400
Subject: [AstroPy] question re specutils
Message-ID: <CAE6Lf2_KaJkeg+WX7_ooe_gy4z3qdS_YPqmX3P0k9HhzZPnAvg@mail.gmail.com>

Hi,

I have a question about one of Astropy's affiliated packages and I hope
someone here can help with it.
I am trying to use specutils' extinction module but it seems I am unable to
import it.

I tried:
import specutils
specutils.extinction.extinction_ccm89(wave, r_v=3.1)
And got:
AttributeError: 'module' object has no attribute 'extinction'

When I tried:
from specutils import extinction
I still got
ImportError: cannot import name extinction

Am I missing something here? I should mention that I was able to use some
of the functionality in spectrum1D.

Thanks,
Aycha

-- 
Aycha Tammour
Astronomy PhD Candidate
University of Western Ontario
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From embray at stsci.edu  Wed Sep 17 11:10:21 2014
From: embray at stsci.edu (Erik Bray)
Date: Wed, 17 Sep 2014 11:10:21 -0400
Subject: [AstroPy] question re specutils
In-Reply-To: <CAE6Lf2_KaJkeg+WX7_ooe_gy4z3qdS_YPqmX3P0k9HhzZPnAvg@mail.gmail.com>
References: <CAE6Lf2_KaJkeg+WX7_ooe_gy4z3qdS_YPqmX3P0k9HhzZPnAvg@mail.gmail.com>
Message-ID: <5419A45D.6060401@stsci.edu>

On 09/17/2014 10:12 AM, Aycha Tammour wrote:
> Hi,
>
> I have a question about one of Astropy's affiliated packages and I hope someone
> here can help with it.
> I am trying to use specutils' extinction module but it seems I am unable to
> import it.
>
> I tried:
> import specutils
> specutils.extinction.extinction_ccm89(wave, r_v=3.1)
> And got:
> AttributeError: 'module' object has no attribute 'extinction'
>
> When I tried:
> from specutils import extinction
> I still got
> ImportError: cannot import name extinction
>
> Am I missing something here? I should mention that I was able to use some of the
> functionality in spectrum1D.

When you import specutils what do

 >>> specutils.__version__

and

 >>> specutils.__file__

show?



From aycha.tammour at gmail.com  Wed Sep 17 11:15:41 2014
From: aycha.tammour at gmail.com (Aycha Tammour)
Date: Wed, 17 Sep 2014 11:15:41 -0400
Subject: [AstroPy] question re specutils
In-Reply-To: <5419A45D.6060401@stsci.edu>
References: <CAE6Lf2_KaJkeg+WX7_ooe_gy4z3qdS_YPqmX3P0k9HhzZPnAvg@mail.gmail.com>
	<5419A45D.6060401@stsci.edu>
Message-ID: <CAE6Lf28Qn0jinqdJYLzOF+q6NtFBQwxmHXJ5KxcZXM-Cud895Q@mail.gmail.com>

Hi Erik,

specutils.__version__
''

specutils.__file__
'specutils/__init__.py'

The package I am using is the one I grabbed from the github repo just
yesterday.

Cheers,
Aycha


On Wed, Sep 17, 2014 at 11:10 AM, Erik Bray <embray at stsci.edu> wrote:

> On 09/17/2014 10:12 AM, Aycha Tammour wrote:
> > Hi,
> >
> > I have a question about one of Astropy's affiliated packages and I hope
> someone
> > here can help with it.
> > I am trying to use specutils' extinction module but it seems I am unable
> to
> > import it.
> >
> > I tried:
> > import specutils
> > specutils.extinction.extinction_ccm89(wave, r_v=3.1)
> > And got:
> > AttributeError: 'module' object has no attribute 'extinction'
> >
> > When I tried:
> > from specutils import extinction
> > I still got
> > ImportError: cannot import name extinction
> >
> > Am I missing something here? I should mention that I was able to use
> some of the
> > functionality in spectrum1D.
>
> When you import specutils what do
>
>  >>> specutils.__version__
>
> and
>
>  >>> specutils.__file__
>
> show?
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>
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From embray at stsci.edu  Wed Sep 17 11:18:00 2014
From: embray at stsci.edu (Erik Bray)
Date: Wed, 17 Sep 2014 11:18:00 -0400
Subject: [AstroPy] question re specutils
In-Reply-To: <CAE6Lf28Qn0jinqdJYLzOF+q6NtFBQwxmHXJ5KxcZXM-Cud895Q@mail.gmail.com>
References: <CAE6Lf2_KaJkeg+WX7_ooe_gy4z3qdS_YPqmX3P0k9HhzZPnAvg@mail.gmail.com>	<5419A45D.6060401@stsci.edu>
	<CAE6Lf28Qn0jinqdJYLzOF+q6NtFBQwxmHXJ5KxcZXM-Cud895Q@mail.gmail.com>
Message-ID: <5419A628.3020108@stsci.edu>

On 09/17/2014 11:15 AM, Aycha Tammour wrote:
> Hi Erik,
>
> specutils.__version__
> ''
>
> specutils.__file__
> 'specutils/__init__.py'
>
> The package I am using is the one I grabbed from the github repo just yesterday.

It sounds like you're just trying to import the package directly out of the 
repository clone without building the package first or installing it.

It looks like specutils doesn't have installation instructions as such, but I 
recommend looking at the installation instructions for Astropy as it applies all 
the same:

http://docs.astropy.org/en/stable/install.html

Erik

> On Wed, Sep 17, 2014 at 11:10 AM, Erik Bray <embray at stsci.edu
> <mailto:embray at stsci.edu>> wrote:
>
>     On 09/17/2014 10:12 AM, Aycha Tammour wrote:
>     > Hi,
>     >
>     > I have a question about one of Astropy's affiliated packages and I hope someone
>     > here can help with it.
>     > I am trying to use specutils' extinction module but it seems I am unable to
>     > import it.
>     >
>     > I tried:
>     > import specutils
>     > specutils.extinction.extinction_ccm89(wave, r_v=3.1)
>     > And got:
>     > AttributeError: 'module' object has no attribute 'extinction'
>     >
>     > When I tried:
>     > from specutils import extinction
>     > I still got
>     > ImportError: cannot import name extinction
>     >
>     > Am I missing something here? I should mention that I was able to use some of the
>     > functionality in spectrum1D.
>
>     When you import specutils what do
>
>       >>> specutils.__version__
>
>     and
>
>       >>> specutils.__file__
>
>     show?
>
>     _______________________________________________
>     AstroPy mailing list
>     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     http://mail.scipy.org/mailman/listinfo/astropy
>
>
>
>
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>



From aycha.tammour at gmail.com  Wed Sep 17 11:46:51 2014
From: aycha.tammour at gmail.com (Aycha Tammour)
Date: Wed, 17 Sep 2014 11:46:51 -0400
Subject: [AstroPy] question re specutils
In-Reply-To: <5419A628.3020108@stsci.edu>
References: <CAE6Lf2_KaJkeg+WX7_ooe_gy4z3qdS_YPqmX3P0k9HhzZPnAvg@mail.gmail.com>
	<5419A45D.6060401@stsci.edu>
	<CAE6Lf28Qn0jinqdJYLzOF+q6NtFBQwxmHXJ5KxcZXM-Cud895Q@mail.gmail.com>
	<5419A628.3020108@stsci.edu>
Message-ID: <CAE6Lf28DVhMWvR7KhSVATg=f-ULNvztaJnYeGRPFLPR30e1PBw@mail.gmail.com>

Thanks Erik. This makes sense but there is actually a setup_package.py file
in the directory which I used to install specutils with

python setup_package.py install

Nothing showed on my terminal which seems a bit suspicious.

-Aycha



On Wed, Sep 17, 2014 at 11:18 AM, Erik Bray <embray at stsci.edu> wrote:

> On 09/17/2014 11:15 AM, Aycha Tammour wrote:
> > Hi Erik,
> >
> > specutils.__version__
> > ''
> >
> > specutils.__file__
> > 'specutils/__init__.py'
> >
> > The package I am using is the one I grabbed from the github repo just
> yesterday.
>
> It sounds like you're just trying to import the package directly out of the
> repository clone without building the package first or installing it.
>
> It looks like specutils doesn't have installation instructions as such,
> but I
> recommend looking at the installation instructions for Astropy as it
> applies all
> the same:
>
> http://docs.astropy.org/en/stable/install.html
>
> Erik
>
> > On Wed, Sep 17, 2014 at 11:10 AM, Erik Bray <embray at stsci.edu
> > <mailto:embray at stsci.edu>> wrote:
> >
> >     On 09/17/2014 10:12 AM, Aycha Tammour wrote:
> >     > Hi,
> >     >
> >     > I have a question about one of Astropy's affiliated packages and I
> hope someone
> >     > here can help with it.
> >     > I am trying to use specutils' extinction module but it seems I am
> unable to
> >     > import it.
> >     >
> >     > I tried:
> >     > import specutils
> >     > specutils.extinction.extinction_ccm89(wave, r_v=3.1)
> >     > And got:
> >     > AttributeError: 'module' object has no attribute 'extinction'
> >     >
> >     > When I tried:
> >     > from specutils import extinction
> >     > I still got
> >     > ImportError: cannot import name extinction
> >     >
> >     > Am I missing something here? I should mention that I was able to
> use some of the
> >     > functionality in spectrum1D.
> >
> >     When you import specutils what do
> >
> >       >>> specutils.__version__
> >
> >     and
> >
> >       >>> specutils.__file__
> >
> >     show?
> >
> >     _______________________________________________
> >     AstroPy mailing list
> >     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     http://mail.scipy.org/mailman/listinfo/astropy
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > AstroPy mailing list
> > AstroPy at scipy.org
> > http://mail.scipy.org/mailman/listinfo/astropy
> >
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>
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From maik.riechert at arcor.de  Wed Sep 17 15:47:56 2014
From: maik.riechert at arcor.de (Maik Riechert)
Date: Wed, 17 Sep 2014 21:47:56 +0200
Subject: [AstroPy] Plot constellations over image with WCS
In-Reply-To: <A1EC8E0B03630149876AA55EEE18C05C5BC5C08F@EXCHMAIL2.stsci.edu>
References: <5418931D.6050601@arcor.de>
	<A1EC8E0B03630149876AA55EEE18C05C5BC5C08F@EXCHMAIL2.stsci.edu>
Message-ID: <5419E56C.8050203@arcor.de>

Hi Marshall,

this looks good. Would you mind adding a license file to your
repository? Otherwise I can't include it in my own software.

Thanks!
Maik

Am 16.09.2014 21:54, schrieb Marshall Perrin:
> Hi Maik, 
> 
> 
> See https://github.com/mperrin/misc_astro/blob/master/constellations.py
> 
> This supports both 2D plots like the ones you indicated, and 3D plots using mpl3d for rotating celestial sphere visualizations. 
> 
> The code is about 3 years old and I haven't tried it with any of the latest WCS visualization tools, but I'd imagine there won't be too many compatibility hurdles. Right now this just expects an Axes instance configured in degrees, and doesn't know anything directly about WCS or astropy coordinates, but it's got all the constellation outlines you're looking for. 
> 
> Hope this helps, 
> 
>  - Marshall
> 
> 
> 
> ________________________________________
> From: astropy-bounces at scipy.org [astropy-bounces at scipy.org] on behalf of Maik Riechert [maik.riechert at arcor.de]
> Sent: Tuesday, September 16, 2014 3:44 PM
> To: Astronomical Python mailing list
> Subject: [AstroPy] Plot constellations over image with WCS
> 
> Hi,
> 
> Google didn't help me a lot so I thought this list is the best place for
> my question.
> 
> What I'm after is drawing constellations over images with WCS info like
> here:
> 
> http://nova.astrometry.net/user_images/401363#annotated
> http://nova.astrometry.net/user_images/401685#annotated
> 
> Is there a Python package that does that? Of not, is there some kind of
> online catalog (using astroquery?) for constellations that I could use?
> A static small offline catalog would be fine too.
> 
> Thanks for suggestions,
> Maik
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
> 



From embray at stsci.edu  Wed Sep 17 16:40:08 2014
From: embray at stsci.edu (Erik Bray)
Date: Wed, 17 Sep 2014 16:40:08 -0400
Subject: [AstroPy] question re specutils
In-Reply-To: <CAE6Lf28DVhMWvR7KhSVATg=f-ULNvztaJnYeGRPFLPR30e1PBw@mail.gmail.com>
References: <CAE6Lf2_KaJkeg+WX7_ooe_gy4z3qdS_YPqmX3P0k9HhzZPnAvg@mail.gmail.com>	<5419A45D.6060401@stsci.edu>	<CAE6Lf28Qn0jinqdJYLzOF+q6NtFBQwxmHXJ5KxcZXM-Cud895Q@mail.gmail.com>	<5419A628.3020108@stsci.edu>
	<CAE6Lf28DVhMWvR7KhSVATg=f-ULNvztaJnYeGRPFLPR30e1PBw@mail.gmail.com>
Message-ID: <5419F1A8.8060604@stsci.edu>

On 09/17/2014 11:46 AM, Aycha Tammour wrote:
> Thanks Erik. This makes sense but there is actually a setup_package.py file in
> the directory which I used to install specutils with
>
> python setup_package.py install
>
> Nothing showed on my terminal which seems a bit suspicious.

setup_package.py is not the file you are looking for.

Please follow the instructions at

http://docs.astropy.org/en/stable/install.html#obtaining-the-source-packages

if you want to install from source, or better still just do `pip install specutils`.

Erik

> On Wed, Sep 17, 2014 at 11:18 AM, Erik Bray <embray at stsci.edu
> <mailto:embray at stsci.edu>> wrote:
>
>     On 09/17/2014 11:15 AM, Aycha Tammour wrote:
>     > Hi Erik,
>     >
>     > specutils.__version__
>     > ''
>     >
>     > specutils.__file__
>     > 'specutils/__init__.py'
>     >
>     > The package I am using is the one I grabbed from the github repo just yesterday.
>
>     It sounds like you're just trying to import the package directly out of the
>     repository clone without building the package first or installing it.
>
>     It looks like specutils doesn't have installation instructions as such, but I
>     recommend looking at the installation instructions for Astropy as it applies all
>     the same:
>
>     http://docs.astropy.org/en/stable/install.html
>
>     Erik
>
>     > On Wed, Sep 17, 2014 at 11:10 AM, Erik Bray <embray at stsci.edu <mailto:embray at stsci.edu>
>      > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>> wrote:
>      >
>      >     On 09/17/2014 10:12 AM, Aycha Tammour wrote:
>      >     > Hi,
>      >     >
>      >     > I have a question about one of Astropy's affiliated packages and I
>     hope someone
>      >     > here can help with it.
>      >     > I am trying to use specutils' extinction module but it seems I am
>     unable to
>      >     > import it.
>      >     >
>      >     > I tried:
>      >     > import specutils
>      >     > specutils.extinction.extinction_ccm89(wave, r_v=3.1)
>      >     > And got:
>      >     > AttributeError: 'module' object has no attribute 'extinction'
>      >     >
>      >     > When I tried:
>      >     > from specutils import extinction
>      >     > I still got
>      >     > ImportError: cannot import name extinction
>      >     >
>      >     > Am I missing something here? I should mention that I was able to
>     use some of the
>      >     > functionality in spectrum1D.
>      >
>      >     When you import specutils what do
>      >
>      >       >>> specutils.__version__
>      >
>      >     and
>      >
>      >       >>> specutils.__file__
>      >
>      >     show?
>      >
>      >     _______________________________________________
>      >     AstroPy mailing list
>      > AstroPy at scipy.org <mailto:AstroPy at scipy.org> <mailto:AstroPy at scipy.org
>     <mailto:AstroPy at scipy.org>>
>      > http://mail.scipy.org/mailman/listinfo/astropy
>      >
>      >
>      >
>      >
>      >
>      >
>      > _______________________________________________
>      > AstroPy mailing list
>      > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>      > http://mail.scipy.org/mailman/listinfo/astropy
>      >
>
>     _______________________________________________
>     AstroPy mailing list
>     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     http://mail.scipy.org/mailman/listinfo/astropy
>
>
>
>
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>



From aycha.tammour at gmail.com  Thu Sep 18 12:20:37 2014
From: aycha.tammour at gmail.com (Aycha Tammour)
Date: Thu, 18 Sep 2014 12:20:37 -0400
Subject: [AstroPy] question re specutils
In-Reply-To: <5419F1A8.8060604@stsci.edu>
References: <CAE6Lf2_KaJkeg+WX7_ooe_gy4z3qdS_YPqmX3P0k9HhzZPnAvg@mail.gmail.com>
	<5419A45D.6060401@stsci.edu>
	<CAE6Lf28Qn0jinqdJYLzOF+q6NtFBQwxmHXJ5KxcZXM-Cud895Q@mail.gmail.com>
	<5419A628.3020108@stsci.edu>
	<CAE6Lf28DVhMWvR7KhSVATg=f-ULNvztaJnYeGRPFLPR30e1PBw@mail.gmail.com>
	<5419F1A8.8060604@stsci.edu>
Message-ID: <CAE6Lf2_5rC1A2BJWbt7ACy_=4Nifd_m+CidS=zML4t0=mFX1=g@mail.gmail.com>

Erik,

pip install specutils was not able to install the package (No distributions
at all found for specutils) even when I tried --allow-unvirified and
--allow-external.

Although pip search specutils seemed to find the package.

I tried installing from source on a MAC and a unix machine and got error
messages about cythoning some file (code.py, I think).

Best,
Aycha

On Wed, Sep 17, 2014 at 4:40 PM, Erik Bray <embray at stsci.edu> wrote:

> On 09/17/2014 11:46 AM, Aycha Tammour wrote:
> > Thanks Erik. This makes sense but there is actually a setup_package.py
> file in
> > the directory which I used to install specutils with
> >
> > python setup_package.py install
> >
> > Nothing showed on my terminal which seems a bit suspicious.
>
> setup_package.py is not the file you are looking for.
>
> Please follow the instructions at
>
>
> http://docs.astropy.org/en/stable/install.html#obtaining-the-source-packages
>
> if you want to install from source, or better still just do `pip install
> specutils`.
>
> Erik
>
> > On Wed, Sep 17, 2014 at 11:18 AM, Erik Bray <embray at stsci.edu
> > <mailto:embray at stsci.edu>> wrote:
> >
> >     On 09/17/2014 11:15 AM, Aycha Tammour wrote:
> >     > Hi Erik,
> >     >
> >     > specutils.__version__
> >     > ''
> >     >
> >     > specutils.__file__
> >     > 'specutils/__init__.py'
> >     >
> >     > The package I am using is the one I grabbed from the github repo
> just yesterday.
> >
> >     It sounds like you're just trying to import the package directly out
> of the
> >     repository clone without building the package first or installing it.
> >
> >     It looks like specutils doesn't have installation instructions as
> such, but I
> >     recommend looking at the installation instructions for Astropy as it
> applies all
> >     the same:
> >
> >     http://docs.astropy.org/en/stable/install.html
> >
> >     Erik
> >
> >     > On Wed, Sep 17, 2014 at 11:10 AM, Erik Bray <embray at stsci.edu
> <mailto:embray at stsci.edu>
> >      > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>> wrote:
> >      >
> >      >     On 09/17/2014 10:12 AM, Aycha Tammour wrote:
> >      >     > Hi,
> >      >     >
> >      >     > I have a question about one of Astropy's affiliated
> packages and I
> >     hope someone
> >      >     > here can help with it.
> >      >     > I am trying to use specutils' extinction module but it
> seems I am
> >     unable to
> >      >     > import it.
> >      >     >
> >      >     > I tried:
> >      >     > import specutils
> >      >     > specutils.extinction.extinction_ccm89(wave, r_v=3.1)
> >      >     > And got:
> >      >     > AttributeError: 'module' object has no attribute
> 'extinction'
> >      >     >
> >      >     > When I tried:
> >      >     > from specutils import extinction
> >      >     > I still got
> >      >     > ImportError: cannot import name extinction
> >      >     >
> >      >     > Am I missing something here? I should mention that I was
> able to
> >     use some of the
> >      >     > functionality in spectrum1D.
> >      >
> >      >     When you import specutils what do
> >      >
> >      >       >>> specutils.__version__
> >      >
> >      >     and
> >      >
> >      >       >>> specutils.__file__
> >      >
> >      >     show?
> >      >
> >      >     _______________________________________________
> >      >     AstroPy mailing list
> >      > AstroPy at scipy.org <mailto:AstroPy at scipy.org> <mailto:
> AstroPy at scipy.org
> >     <mailto:AstroPy at scipy.org>>
> >      > http://mail.scipy.org/mailman/listinfo/astropy
> >      >
> >      >
> >      >
> >      >
> >      >
> >      >
> >      > _______________________________________________
> >      > AstroPy mailing list
> >      > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >      > http://mail.scipy.org/mailman/listinfo/astropy
> >      >
> >
> >     _______________________________________________
> >     AstroPy mailing list
> >     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     http://mail.scipy.org/mailman/listinfo/astropy
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > AstroPy mailing list
> > AstroPy at scipy.org
> > http://mail.scipy.org/mailman/listinfo/astropy
> >
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>



-- 
Aycha Tammour
Astronomy PhD Candidate
University of Western Ontario
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From embray at stsci.edu  Thu Sep 18 13:10:04 2014
From: embray at stsci.edu (Erik Bray)
Date: Thu, 18 Sep 2014 13:10:04 -0400
Subject: [AstroPy] question re specutils
In-Reply-To: <CAE6Lf2_5rC1A2BJWbt7ACy_=4Nifd_m+CidS=zML4t0=mFX1=g@mail.gmail.com>
References: <CAE6Lf2_KaJkeg+WX7_ooe_gy4z3qdS_YPqmX3P0k9HhzZPnAvg@mail.gmail.com>	<5419A45D.6060401@stsci.edu>	<CAE6Lf28Qn0jinqdJYLzOF+q6NtFBQwxmHXJ5KxcZXM-Cud895Q@mail.gmail.com>	<5419A628.3020108@stsci.edu>	<CAE6Lf28DVhMWvR7KhSVATg=f-ULNvztaJnYeGRPFLPR30e1PBw@mail.gmail.com>	<5419F1A8.8060604@stsci.edu>
	<CAE6Lf2_5rC1A2BJWbt7ACy_=4Nifd_m+CidS=zML4t0=mFX1=g@mail.gmail.com>
Message-ID: <541B11EC.1070607@stsci.edu>

On 09/18/2014 12:20 PM, Aycha Tammour wrote:
> Erik,
>
> pip install specutils was not able to install the package (No distributions at
> all found for specutils) even when I tried --allow-unvirified and --allow-external.
>
> Although pip search specutils seemed to find the package.

Sorry, I may have sent you down the wrong path by suggesting pip.  I don't think 
specutils has had any releases to PyPI yet.  What I had in mind was something like:

$ pip install git+https://github.com/astropy/specutils.git

To just install directly from the git repo.

> I tried installing from source on a MAC and a unix machine and got error
> messages about cythoning some file (code.py, I think).

Do you have Cython installed?

Erik


> On Wed, Sep 17, 2014 at 4:40 PM, Erik Bray <embray at stsci.edu
> <mailto:embray at stsci.edu>> wrote:
>
>     On 09/17/2014 11:46 AM, Aycha Tammour wrote:
>     > Thanks Erik. This makes sense but there is actually a setup_package.py file in
>     > the directory which I used to install specutils with
>     >
>     > python setup_package.py install
>     >
>     > Nothing showed on my terminal which seems a bit suspicious.
>
>     setup_package.py is not the file you are looking for.
>
>     Please follow the instructions at
>
>     http://docs.astropy.org/en/stable/install.html#obtaining-the-source-packages
>
>     if you want to install from source, or better still just do `pip install
>     specutils`.
>
>     Erik
>
>     > On Wed, Sep 17, 2014 at 11:18 AM, Erik Bray <embray at stsci.edu <mailto:embray at stsci.edu>
>     > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>> wrote:
>     >
>     >     On 09/17/2014 11:15 AM, Aycha Tammour wrote:
>     >     > Hi Erik,
>     >     >
>     >     > specutils.__version__
>     >     > ''
>     >     >
>     >     > specutils.__file__
>     >     > 'specutils/__init__.py'
>     >     >
>     >     > The package I am using is the one I grabbed from the github repo just yesterday.
>     >
>     >     It sounds like you're just trying to import the package directly out of the
>     >     repository clone without building the package first or installing it.
>     >
>     >     It looks like specutils doesn't have installation instructions as such, but I
>     >     recommend looking at the installation instructions for Astropy as it applies all
>     >     the same:
>     >
>     >http://docs.astropy.org/en/stable/install.html
>     >
>     >     Erik
>     >
>     >     > On Wed, Sep 17, 2014 at 11:10 AM, Erik Bray <embray at stsci.edu <mailto:embray at stsci.edu> <mailto:embray at stsci.edu
>     <mailto:embray at stsci.edu>>
>      >      > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>
>     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>>> wrote:
>      >      >
>      >      >     On 09/17/2014 10:12 AM, Aycha Tammour wrote:
>      >      >     > Hi,
>      >      >     >
>      >      >     > I have a question about one of Astropy's affiliated packages
>     and I
>      >     hope someone
>      >      >     > here can help with it.
>      >      >     > I am trying to use specutils' extinction module but it seems
>     I am
>      >     unable to
>      >      >     > import it.
>      >      >     >
>      >      >     > I tried:
>      >      >     > import specutils
>      >      >     > specutils.extinction.extinction_ccm89(wave, r_v=3.1)
>      >      >     > And got:
>      >      >     > AttributeError: 'module' object has no attribute 'extinction'
>      >      >     >
>      >      >     > When I tried:
>      >      >     > from specutils import extinction
>      >      >     > I still got
>      >      >     > ImportError: cannot import name extinction
>      >      >     >
>      >      >     > Am I missing something here? I should mention that I was able to
>      >     use some of the
>      >      >     > functionality in spectrum1D.
>      >      >
>      >      >     When you import specutils what do
>      >      >
>      >      >       >>> specutils.__version__
>      >      >
>      >      >     and
>      >      >
>      >      >       >>> specutils.__file__
>      >      >
>      >      >     show?



From thomas.robitaille at gmail.com  Thu Sep 18 13:39:09 2014
From: thomas.robitaille at gmail.com (Thomas Robitaille)
Date: Thu, 18 Sep 2014 19:39:09 +0200
Subject: [AstroPy] question re specutils
In-Reply-To: <CAE6Lf2_5rC1A2BJWbt7ACy_=4Nifd_m+CidS=zML4t0=mFX1=g@mail.gmail.com>
References: <CAE6Lf2_KaJkeg+WX7_ooe_gy4z3qdS_YPqmX3P0k9HhzZPnAvg@mail.gmail.com>
	<5419A45D.6060401@stsci.edu>
	<CAE6Lf28Qn0jinqdJYLzOF+q6NtFBQwxmHXJ5KxcZXM-Cud895Q@mail.gmail.com>
	<5419A628.3020108@stsci.edu>
	<CAE6Lf28DVhMWvR7KhSVATg=f-ULNvztaJnYeGRPFLPR30e1PBw@mail.gmail.com>
	<5419F1A8.8060604@stsci.edu>
	<CAE6Lf2_5rC1A2BJWbt7ACy_=4Nifd_m+CidS=zML4t0=mFX1=g@mail.gmail.com>
Message-ID: <541B18BD.6010004@gmail.com>

Hi Aycha,

Just to echo what Erik Bray said, there hasn't actually been a specutils
release yet, so in addition to meaning that it is a bit harder to
install, the package may not be ready for 'science' use yet (and the API
may not be stable).

Maybe Wolfgang or someone else involved in specutils can give an update
on the current status?

Cheers,
Tom

Aycha Tammour wrote:
> Erik,
> 
> pip install specutils was not able to install the package (No
> distributions at all found for specutils) even when I tried
> --allow-unvirified and --allow-external.
> 
> Although pip search specutils seemed to find the package.
> 
> I tried installing from source on a MAC and a unix machine and got error
> messages about cythoning some file (code.py, I think).
> 
> Best,
> Aycha
> 
> On Wed, Sep 17, 2014 at 4:40 PM, Erik Bray <embray at stsci.edu
> <mailto:embray at stsci.edu>> wrote:
> 
>     On 09/17/2014 11:46 AM, Aycha Tammour wrote:
>     > Thanks Erik. This makes sense but there is actually a
>     setup_package.py file in
>     > the directory which I used to install specutils with
>     >
>     > python setup_package.py install
>     >
>     > Nothing showed on my terminal which seems a bit suspicious.
> 
>     setup_package.py is not the file you are looking for.
> 
>     Please follow the instructions at
> 
>     http://docs.astropy.org/en/stable/install.html#obtaining-the-source-packages
> 
>     if you want to install from source, or better still just do `pip
>     install specutils`.
> 
>     Erik
> 
>     > On Wed, Sep 17, 2014 at 11:18 AM, Erik Bray <embray at stsci.edu
>     <mailto:embray at stsci.edu>
>     > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>> wrote:
>     >
>     >     On 09/17/2014 11:15 AM, Aycha Tammour wrote:
>     >     > Hi Erik,
>     >     >
>     >     > specutils.__version__
>     >     > ''
>     >     >
>     >     > specutils.__file__
>     >     > 'specutils/__init__.py'
>     >     >
>     >     > The package I am using is the one I grabbed from the github
>     repo just yesterday.
>     >
>     >     It sounds like you're just trying to import the package
>     directly out of the
>     >     repository clone without building the package first or
>     installing it.
>     >
>     >     It looks like specutils doesn't have installation instructions
>     as such, but I
>     >     recommend looking at the installation instructions for Astropy
>     as it applies all
>     >     the same:
>     >
>     >     http://docs.astropy.org/en/stable/install.html
>     >
>     >     Erik
>     >
>     >     > On Wed, Sep 17, 2014 at 11:10 AM, Erik Bray <embray at stsci.edu
>     <mailto:embray at stsci.edu> <mailto:embray at stsci.edu
>     <mailto:embray at stsci.edu>>
>     >      > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>
>     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>>> wrote:
>     >      >
>     >      >     On 09/17/2014 10:12 AM, Aycha Tammour wrote:
>     >      >     > Hi,
>     >      >     >
>     >      >     > I have a question about one of Astropy's affiliated
>     packages and I
>     >     hope someone
>     >      >     > here can help with it.
>     >      >     > I am trying to use specutils' extinction module but
>     it seems I am
>     >     unable to
>     >      >     > import it.
>     >      >     >
>     >      >     > I tried:
>     >      >     > import specutils
>     >      >     > specutils.extinction.extinction_ccm89(wave, r_v=3.1)
>     >      >     > And got:
>     >      >     > AttributeError: 'module' object has no attribute
>     'extinction'
>     >      >     >
>     >      >     > When I tried:
>     >      >     > from specutils import extinction
>     >      >     > I still got
>     >      >     > ImportError: cannot import name extinction
>     >      >     >
>     >      >     > Am I missing something here? I should mention that I
>     was able to
>     >     use some of the
>     >      >     > functionality in spectrum1D.
>     >      >
>     >      >     When you import specutils what do
>     >      >
>     >      >       >>> specutils.__version__
>     >      >
>     >      >     and
>     >      >
>     >      >       >>> specutils.__file__
>     >      >
>     >      >     show?
>     >      >
>     >      >     _______________________________________________
>     >      >     AstroPy mailing list
>     >      > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
>     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>>
>     >      > http://mail.scipy.org/mailman/listinfo/astropy
>     >      >
>     >      >
>     >      >
>     >      >
>     >      >
>     >      >
>     >      > _______________________________________________
>     >      > AstroPy mailing list
>     >      > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
>     >      > http://mail.scipy.org/mailman/listinfo/astropy
>     >      >
>     >
>     >     _______________________________________________
>     >     AstroPy mailing list
>     >     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
>     >     http://mail.scipy.org/mailman/listinfo/astropy
>     >
>     >
>     >
>     >
>     >
>     >
>     > _______________________________________________
>     > AstroPy mailing list
>     > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     > http://mail.scipy.org/mailman/listinfo/astropy
>     >
> 
>     _______________________________________________
>     AstroPy mailing list
>     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     http://mail.scipy.org/mailman/listinfo/astropy
> 
> 
> 
> 
> -- 
> Aycha Tammour
> Astronomy PhD Candidate
> University of Western Ontario
> 
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy


From wkerzendorf at gmail.com  Thu Sep 18 15:59:29 2014
From: wkerzendorf at gmail.com (Wolfgang Kerzendorf)
Date: Thu, 18 Sep 2014 15:59:29 -0400
Subject: [AstroPy] question re specutils
In-Reply-To: <541B18BD.6010004@gmail.com>
References: <CAE6Lf2_KaJkeg+WX7_ooe_gy4z3qdS_YPqmX3P0k9HhzZPnAvg@mail.gmail.com>
	<5419A45D.6060401@stsci.edu>
	<CAE6Lf28Qn0jinqdJYLzOF+q6NtFBQwxmHXJ5KxcZXM-Cud895Q@mail.gmail.com>
	<5419A628.3020108@stsci.edu>
	<CAE6Lf28DVhMWvR7KhSVATg=f-ULNvztaJnYeGRPFLPR30e1PBw@mail.gmail.com>
	<5419F1A8.8060604@stsci.edu>
	<CAE6Lf2_5rC1A2BJWbt7ACy_=4Nifd_m+CidS=zML4t0=mFX1=g@mail.gmail.com>
	<541B18BD.6010004@gmail.com>
Message-ID: <CAH33GGE+tdums-43ja_Zsdeqj84TiFz0EMxfWW13mmNO45aw=g@mail.gmail.com>

Hi Aycha,

Erik B. has already given a relatively good instruction how to install
specutils. As Tom R. said there has not been an official release of
specutils, however it is ready for science (and is also being used for that
;-) ). Obviously it depends on what the science you want to do. Kyle et al.
has written the extinction part and documentation and it is mostly ready
for consumption (I used it a couple of times).

It is pretty clearly laid out in the document that Erik sent (
http://docs.astropy.org/en/stable/install.html#obtaining-the-source-packages)
 of what to do -- including the need to install cython.

Let us know how it goes,
    Wolfgang

On Thu, Sep 18, 2014 at 1:39 PM, Thomas Robitaille <
thomas.robitaille at gmail.com> wrote:

> Hi Aycha,
>
> Just to echo what Erik Bray said, there hasn't actually been a specutils
> release yet, so in addition to meaning that it is a bit harder to
> install, the package may not be ready for 'science' use yet (and the API
> may not be stable).
>
> Maybe Wolfgang or someone else involved in specutils can give an update
> on the current status?
>
> Cheers,
> Tom
>
> Aycha Tammour wrote:
> > Erik,
> >
> > pip install specutils was not able to install the package (No
> > distributions at all found for specutils) even when I tried
> > --allow-unvirified and --allow-external.
> >
> > Although pip search specutils seemed to find the package.
> >
> > I tried installing from source on a MAC and a unix machine and got error
> > messages about cythoning some file (code.py, I think).
> >
> > Best,
> > Aycha
> >
> > On Wed, Sep 17, 2014 at 4:40 PM, Erik Bray <embray at stsci.edu
> > <mailto:embray at stsci.edu>> wrote:
> >
> >     On 09/17/2014 11:46 AM, Aycha Tammour wrote:
> >     > Thanks Erik. This makes sense but there is actually a
> >     setup_package.py file in
> >     > the directory which I used to install specutils with
> >     >
> >     > python setup_package.py install
> >     >
> >     > Nothing showed on my terminal which seems a bit suspicious.
> >
> >     setup_package.py is not the file you are looking for.
> >
> >     Please follow the instructions at
> >
> >
> http://docs.astropy.org/en/stable/install.html#obtaining-the-source-packages
> >
> >     if you want to install from source, or better still just do `pip
> >     install specutils`.
> >
> >     Erik
> >
> >     > On Wed, Sep 17, 2014 at 11:18 AM, Erik Bray <embray at stsci.edu
> >     <mailto:embray at stsci.edu>
> >     > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>> wrote:
> >     >
> >     >     On 09/17/2014 11:15 AM, Aycha Tammour wrote:
> >     >     > Hi Erik,
> >     >     >
> >     >     > specutils.__version__
> >     >     > ''
> >     >     >
> >     >     > specutils.__file__
> >     >     > 'specutils/__init__.py'
> >     >     >
> >     >     > The package I am using is the one I grabbed from the github
> >     repo just yesterday.
> >     >
> >     >     It sounds like you're just trying to import the package
> >     directly out of the
> >     >     repository clone without building the package first or
> >     installing it.
> >     >
> >     >     It looks like specutils doesn't have installation instructions
> >     as such, but I
> >     >     recommend looking at the installation instructions for Astropy
> >     as it applies all
> >     >     the same:
> >     >
> >     >     http://docs.astropy.org/en/stable/install.html
> >     >
> >     >     Erik
> >     >
> >     >     > On Wed, Sep 17, 2014 at 11:10 AM, Erik Bray <
> embray at stsci.edu
> >     <mailto:embray at stsci.edu> <mailto:embray at stsci.edu
> >     <mailto:embray at stsci.edu>>
> >     >      > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>
> >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>>> wrote:
> >     >      >
> >     >      >     On 09/17/2014 10:12 AM, Aycha Tammour wrote:
> >     >      >     > Hi,
> >     >      >     >
> >     >      >     > I have a question about one of Astropy's affiliated
> >     packages and I
> >     >     hope someone
> >     >      >     > here can help with it.
> >     >      >     > I am trying to use specutils' extinction module but
> >     it seems I am
> >     >     unable to
> >     >      >     > import it.
> >     >      >     >
> >     >      >     > I tried:
> >     >      >     > import specutils
> >     >      >     > specutils.extinction.extinction_ccm89(wave, r_v=3.1)
> >     >      >     > And got:
> >     >      >     > AttributeError: 'module' object has no attribute
> >     'extinction'
> >     >      >     >
> >     >      >     > When I tried:
> >     >      >     > from specutils import extinction
> >     >      >     > I still got
> >     >      >     > ImportError: cannot import name extinction
> >     >      >     >
> >     >      >     > Am I missing something here? I should mention that I
> >     was able to
> >     >     use some of the
> >     >      >     > functionality in spectrum1D.
> >     >      >
> >     >      >     When you import specutils what do
> >     >      >
> >     >      >       >>> specutils.__version__
> >     >      >
> >     >      >     and
> >     >      >
> >     >      >       >>> specutils.__file__
> >     >      >
> >     >      >     show?
> >     >      >
> >     >      >     _______________________________________________
> >     >      >     AstroPy mailing list
> >     >      > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>>
> >     >      > http://mail.scipy.org/mailman/listinfo/astropy
> >     >      >
> >     >      >
> >     >      >
> >     >      >
> >     >      >
> >     >      >
> >     >      > _______________________________________________
> >     >      > AstroPy mailing list
> >     >      > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
> >     >      > http://mail.scipy.org/mailman/listinfo/astropy
> >     >      >
> >     >
> >     >     _______________________________________________
> >     >     AstroPy mailing list
> >     >     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
> >     >     http://mail.scipy.org/mailman/listinfo/astropy
> >     >
> >     >
> >     >
> >     >
> >     >
> >     >
> >     > _______________________________________________
> >     > AstroPy mailing list
> >     > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     > http://mail.scipy.org/mailman/listinfo/astropy
> >     >
> >
> >     _______________________________________________
> >     AstroPy mailing list
> >     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     http://mail.scipy.org/mailman/listinfo/astropy
> >
> >
> >
> >
> > --
> > Aycha Tammour
> > Astronomy PhD Candidate
> > University of Western Ontario
> >
> > _______________________________________________
> > AstroPy mailing list
> > AstroPy at scipy.org
> > http://mail.scipy.org/mailman/listinfo/astropy
>
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From thomas.robitaille at gmail.com  Thu Sep 18 16:15:49 2014
From: thomas.robitaille at gmail.com (Thomas Robitaille)
Date: Thu, 18 Sep 2014 22:15:49 +0200
Subject: [AstroPy] question re specutils
In-Reply-To: <CAH33GGE+tdums-43ja_Zsdeqj84TiFz0EMxfWW13mmNO45aw=g@mail.gmail.com>
References: <CAE6Lf2_KaJkeg+WX7_ooe_gy4z3qdS_YPqmX3P0k9HhzZPnAvg@mail.gmail.com>
	<5419A45D.6060401@stsci.edu>
	<CAE6Lf28Qn0jinqdJYLzOF+q6NtFBQwxmHXJ5KxcZXM-Cud895Q@mail.gmail.com>
	<5419A628.3020108@stsci.edu>
	<CAE6Lf28DVhMWvR7KhSVATg=f-ULNvztaJnYeGRPFLPR30e1PBw@mail.gmail.com>
	<5419F1A8.8060604@stsci.edu>
	<CAE6Lf2_5rC1A2BJWbt7ACy_=4Nifd_m+CidS=zML4t0=mFX1=g@mail.gmail.com>
	<541B18BD.6010004@gmail.com>
	<CAH33GGE+tdums-43ja_Zsdeqj84TiFz0EMxfWW13mmNO45aw=g@mail.gmail.com>
Message-ID: <541B3D75.6000209@gmail.com>

Hi Wolfgang,

Thanks for clarifying this! Are there plans for a 0.1 release, since
this would make it easier for people to try it out?

Cheers,
Tom

Wolfgang Kerzendorf wrote:
> Hi Aycha,
> 
> Erik B. has already given a relatively good instruction how to install
> specutils. As Tom R. said there has not been an official release of
> specutils, however it is ready for science (and is also being used for
> that ;-) ). Obviously it depends on what the science you want to do.
> Kyle et al. has written the extinction part and documentation and it is
> mostly ready for consumption (I used it a couple of times). 
> 
> It is pretty clearly laid out in the document that Erik sent
> (http://docs.astropy.org/en/stable/install.html#obtaining-the-source-packages)
>  of what to do -- including the need to install cython. 
> 
> Let us know how it goes,
>     Wolfgang
> 
> On Thu, Sep 18, 2014 at 1:39 PM, Thomas Robitaille
> <thomas.robitaille at gmail.com <mailto:thomas.robitaille at gmail.com>> wrote:
> 
>     Hi Aycha,
> 
>     Just to echo what Erik Bray said, there hasn't actually been a specutils
>     release yet, so in addition to meaning that it is a bit harder to
>     install, the package may not be ready for 'science' use yet (and the API
>     may not be stable).
> 
>     Maybe Wolfgang or someone else involved in specutils can give an update
>     on the current status?
> 
>     Cheers,
>     Tom
> 
>     Aycha Tammour wrote:
>     > Erik,
>     >
>     > pip install specutils was not able to install the package (No
>     > distributions at all found for specutils) even when I tried
>     > --allow-unvirified and --allow-external.
>     >
>     > Although pip search specutils seemed to find the package.
>     >
>     > I tried installing from source on a MAC and a unix machine and got
>     error
>     > messages about cythoning some file (code.py, I think).
>     >
>     > Best,
>     > Aycha
>     >
>     > On Wed, Sep 17, 2014 at 4:40 PM, Erik Bray <embray at stsci.edu
>     <mailto:embray at stsci.edu>
>     > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>> wrote:
>     >
>     >     On 09/17/2014 11:46 AM, Aycha Tammour wrote:
>     >     > Thanks Erik. This makes sense but there is actually a
>     >     setup_package.py file in
>     >     > the directory which I used to install specutils with
>     >     >
>     >     > python setup_package.py install
>     >     >
>     >     > Nothing showed on my terminal which seems a bit suspicious.
>     >
>     >     setup_package.py is not the file you are looking for.
>     >
>     >     Please follow the instructions at
>     >
>     >   
>      http://docs.astropy.org/en/stable/install.html#obtaining-the-source-packages
>     >
>     >     if you want to install from source, or better still just do `pip
>     >     install specutils`.
>     >
>     >     Erik
>     >
>     >     > On Wed, Sep 17, 2014 at 11:18 AM, Erik Bray <embray at stsci.edu
>     <mailto:embray at stsci.edu>
>     >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>
>     >     > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>
>     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>>> wrote:
>     >     >
>     >     >     On 09/17/2014 11:15 AM, Aycha Tammour wrote:
>     >     >     > Hi Erik,
>     >     >     >
>     >     >     > specutils.__version__
>     >     >     > ''
>     >     >     >
>     >     >     > specutils.__file__
>     >     >     > 'specutils/__init__.py'
>     >     >     >
>     >     >     > The package I am using is the one I grabbed from the
>     github
>     >     repo just yesterday.
>     >     >
>     >     >     It sounds like you're just trying to import the package
>     >     directly out of the
>     >     >     repository clone without building the package first or
>     >     installing it.
>     >     >
>     >     >     It looks like specutils doesn't have installation
>     instructions
>     >     as such, but I
>     >     >     recommend looking at the installation instructions for
>     Astropy
>     >     as it applies all
>     >     >     the same:
>     >     >
>     >     >     http://docs.astropy.org/en/stable/install.html
>     >     >
>     >     >     Erik
>     >     >
>     >     >     > On Wed, Sep 17, 2014 at 11:10 AM, Erik Bray
>     <embray at stsci.edu <mailto:embray at stsci.edu>
>     >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>
>     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>
>     >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>>
>     >     >      > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>
>     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>
>     >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>
>     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>>>> wrote:
>     >     >      >
>     >     >      >     On 09/17/2014 10:12 AM, Aycha Tammour wrote:
>     >     >      >     > Hi,
>     >     >      >     >
>     >     >      >     > I have a question about one of Astropy's affiliated
>     >     packages and I
>     >     >     hope someone
>     >     >      >     > here can help with it.
>     >     >      >     > I am trying to use specutils' extinction module but
>     >     it seems I am
>     >     >     unable to
>     >     >      >     > import it.
>     >     >      >     >
>     >     >      >     > I tried:
>     >     >      >     > import specutils
>     >     >      >     > specutils.extinction.extinction_ccm89(wave,
>     r_v=3.1)
>     >     >      >     > And got:
>     >     >      >     > AttributeError: 'module' object has no attribute
>     >     'extinction'
>     >     >      >     >
>     >     >      >     > When I tried:
>     >     >      >     > from specutils import extinction
>     >     >      >     > I still got
>     >     >      >     > ImportError: cannot import name extinction
>     >     >      >     >
>     >     >      >     > Am I missing something here? I should mention
>     that I
>     >     was able to
>     >     >     use some of the
>     >     >      >     > functionality in spectrum1D.
>     >     >      >
>     >     >      >     When you import specutils what do
>     >     >      >
>     >     >      >       >>> specutils.__version__
>     >     >      >
>     >     >      >     and
>     >     >      >
>     >     >      >       >>> specutils.__file__
>     >     >      >
>     >     >      >     show?
>     >     >      >
>     >     >      >     _______________________________________________
>     >     >      >     AstroPy mailing list
>     >     >      > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
>     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>>
>     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
>     >     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>>>
>     >     >      > http://mail.scipy.org/mailman/listinfo/astropy
>     >     >      >
>     >     >      >
>     >     >      >
>     >     >      >
>     >     >      >
>     >     >      >
>     >     >      > _______________________________________________
>     >     >      > AstroPy mailing list
>     >     >      > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
>     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>>
>     >     >      > http://mail.scipy.org/mailman/listinfo/astropy
>     >     >      >
>     >     >
>     >     >     _______________________________________________
>     >     >     AstroPy mailing list
>     >     >     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
>     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>>
>     >     >     http://mail.scipy.org/mailman/listinfo/astropy
>     >     >
>     >     >
>     >     >
>     >     >
>     >     >
>     >     >
>     >     > _______________________________________________
>     >     > AstroPy mailing list
>     >     > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
>     >     > http://mail.scipy.org/mailman/listinfo/astropy
>     >     >
>     >
>     >     _______________________________________________
>     >     AstroPy mailing list
>     >     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
>     >     http://mail.scipy.org/mailman/listinfo/astropy
>     >
>     >
>     >
>     >
>     > --
>     > Aycha Tammour
>     > Astronomy PhD Candidate
>     > University of Western Ontario
>     >
>     > _______________________________________________
>     > AstroPy mailing list
>     > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
>     > http://mail.scipy.org/mailman/listinfo/astropy
> 
> 
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy


From aycha.tammour at gmail.com  Thu Sep 18 16:44:48 2014
From: aycha.tammour at gmail.com (Aycha Tammour)
Date: Thu, 18 Sep 2014 16:44:48 -0400
Subject: [AstroPy] question re specutils
In-Reply-To: <541B3D75.6000209@gmail.com>
References: <CAE6Lf2_KaJkeg+WX7_ooe_gy4z3qdS_YPqmX3P0k9HhzZPnAvg@mail.gmail.com>
	<5419A45D.6060401@stsci.edu>
	<CAE6Lf28Qn0jinqdJYLzOF+q6NtFBQwxmHXJ5KxcZXM-Cud895Q@mail.gmail.com>
	<5419A628.3020108@stsci.edu>
	<CAE6Lf28DVhMWvR7KhSVATg=f-ULNvztaJnYeGRPFLPR30e1PBw@mail.gmail.com>
	<5419F1A8.8060604@stsci.edu>
	<CAE6Lf2_5rC1A2BJWbt7ACy_=4Nifd_m+CidS=zML4t0=mFX1=g@mail.gmail.com>
	<541B18BD.6010004@gmail.com>
	<CAH33GGE+tdums-43ja_Zsdeqj84TiFz0EMxfWW13mmNO45aw=g@mail.gmail.com>
	<541B3D75.6000209@gmail.com>
Message-ID: <CAE6Lf282UXUDVmxWs0OEObDaQVsq4vC18TR-WdfWNRJi_ZQLig@mail.gmail.com>

Hi all and thanks for the feedback! Upgrading my cython fixed the problem.

Cheers,
Aycha

On Thu, Sep 18, 2014 at 4:15 PM, Thomas Robitaille <
thomas.robitaille at gmail.com> wrote:

> Hi Wolfgang,
>
> Thanks for clarifying this! Are there plans for a 0.1 release, since
> this would make it easier for people to try it out?
>
> Cheers,
> Tom
>
> Wolfgang Kerzendorf wrote:
> > Hi Aycha,
> >
> > Erik B. has already given a relatively good instruction how to install
> > specutils. As Tom R. said there has not been an official release of
> > specutils, however it is ready for science (and is also being used for
> > that ;-) ). Obviously it depends on what the science you want to do.
> > Kyle et al. has written the extinction part and documentation and it is
> > mostly ready for consumption (I used it a couple of times).
> >
> > It is pretty clearly laid out in the document that Erik sent
> > (
> http://docs.astropy.org/en/stable/install.html#obtaining-the-source-packages
> )
> >  of what to do -- including the need to install cython.
> >
> > Let us know how it goes,
> >     Wolfgang
> >
> > On Thu, Sep 18, 2014 at 1:39 PM, Thomas Robitaille
> > <thomas.robitaille at gmail.com <mailto:thomas.robitaille at gmail.com>>
> wrote:
> >
> >     Hi Aycha,
> >
> >     Just to echo what Erik Bray said, there hasn't actually been a
> specutils
> >     release yet, so in addition to meaning that it is a bit harder to
> >     install, the package may not be ready for 'science' use yet (and the
> API
> >     may not be stable).
> >
> >     Maybe Wolfgang or someone else involved in specutils can give an
> update
> >     on the current status?
> >
> >     Cheers,
> >     Tom
> >
> >     Aycha Tammour wrote:
> >     > Erik,
> >     >
> >     > pip install specutils was not able to install the package (No
> >     > distributions at all found for specutils) even when I tried
> >     > --allow-unvirified and --allow-external.
> >     >
> >     > Although pip search specutils seemed to find the package.
> >     >
> >     > I tried installing from source on a MAC and a unix machine and got
> >     error
> >     > messages about cythoning some file (code.py, I think).
> >     >
> >     > Best,
> >     > Aycha
> >     >
> >     > On Wed, Sep 17, 2014 at 4:40 PM, Erik Bray <embray at stsci.edu
> >     <mailto:embray at stsci.edu>
> >     > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>> wrote:
> >     >
> >     >     On 09/17/2014 11:46 AM, Aycha Tammour wrote:
> >     >     > Thanks Erik. This makes sense but there is actually a
> >     >     setup_package.py file in
> >     >     > the directory which I used to install specutils with
> >     >     >
> >     >     > python setup_package.py install
> >     >     >
> >     >     > Nothing showed on my terminal which seems a bit suspicious.
> >     >
> >     >     setup_package.py is not the file you are looking for.
> >     >
> >     >     Please follow the instructions at
> >     >
> >     >
> >
> http://docs.astropy.org/en/stable/install.html#obtaining-the-source-packages
> >     >
> >     >     if you want to install from source, or better still just do
> `pip
> >     >     install specutils`.
> >     >
> >     >     Erik
> >     >
> >     >     > On Wed, Sep 17, 2014 at 11:18 AM, Erik Bray <
> embray at stsci.edu
> >     <mailto:embray at stsci.edu>
> >     >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>
> >     >     > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>
> >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>>> wrote:
> >     >     >
> >     >     >     On 09/17/2014 11:15 AM, Aycha Tammour wrote:
> >     >     >     > Hi Erik,
> >     >     >     >
> >     >     >     > specutils.__version__
> >     >     >     > ''
> >     >     >     >
> >     >     >     > specutils.__file__
> >     >     >     > 'specutils/__init__.py'
> >     >     >     >
> >     >     >     > The package I am using is the one I grabbed from the
> >     github
> >     >     repo just yesterday.
> >     >     >
> >     >     >     It sounds like you're just trying to import the package
> >     >     directly out of the
> >     >     >     repository clone without building the package first or
> >     >     installing it.
> >     >     >
> >     >     >     It looks like specutils doesn't have installation
> >     instructions
> >     >     as such, but I
> >     >     >     recommend looking at the installation instructions for
> >     Astropy
> >     >     as it applies all
> >     >     >     the same:
> >     >     >
> >     >     >     http://docs.astropy.org/en/stable/install.html
> >     >     >
> >     >     >     Erik
> >     >     >
> >     >     >     > On Wed, Sep 17, 2014 at 11:10 AM, Erik Bray
> >     <embray at stsci.edu <mailto:embray at stsci.edu>
> >     >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>
> >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>
> >     >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>>
> >     >     >      > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>
> >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>
> >     >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>
> >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>>>> wrote:
> >     >     >      >
> >     >     >      >     On 09/17/2014 10:12 AM, Aycha Tammour wrote:
> >     >     >      >     > Hi,
> >     >     >      >     >
> >     >     >      >     > I have a question about one of Astropy's
> affiliated
> >     >     packages and I
> >     >     >     hope someone
> >     >     >      >     > here can help with it.
> >     >     >      >     > I am trying to use specutils' extinction module
> but
> >     >     it seems I am
> >     >     >     unable to
> >     >     >      >     > import it.
> >     >     >      >     >
> >     >     >      >     > I tried:
> >     >     >      >     > import specutils
> >     >     >      >     > specutils.extinction.extinction_ccm89(wave,
> >     r_v=3.1)
> >     >     >      >     > And got:
> >     >     >      >     > AttributeError: 'module' object has no attribute
> >     >     'extinction'
> >     >     >      >     >
> >     >     >      >     > When I tried:
> >     >     >      >     > from specutils import extinction
> >     >     >      >     > I still got
> >     >     >      >     > ImportError: cannot import name extinction
> >     >     >      >     >
> >     >     >      >     > Am I missing something here? I should mention
> >     that I
> >     >     was able to
> >     >     >     use some of the
> >     >     >      >     > functionality in spectrum1D.
> >     >     >      >
> >     >     >      >     When you import specutils what do
> >     >     >      >
> >     >     >      >       >>> specutils.__version__
> >     >     >      >
> >     >     >      >     and
> >     >     >      >
> >     >     >      >       >>> specutils.__file__
> >     >     >      >
> >     >     >      >     show?
> >     >     >      >
> >     >     >      >     _______________________________________________
> >     >     >      >     AstroPy mailing list
> >     >     >      > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
> >     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>>
> >     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
> >     >     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>>>
> >     >     >      > http://mail.scipy.org/mailman/listinfo/astropy
> >     >     >      >
> >     >     >      >
> >     >     >      >
> >     >     >      >
> >     >     >      >
> >     >     >      >
> >     >     >      > _______________________________________________
> >     >     >      > AstroPy mailing list
> >     >     >      > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
> >     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>>
> >     >     >      > http://mail.scipy.org/mailman/listinfo/astropy
> >     >     >      >
> >     >     >
> >     >     >     _______________________________________________
> >     >     >     AstroPy mailing list
> >     >     >     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
> >     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>>
> >     >     >     http://mail.scipy.org/mailman/listinfo/astropy
> >     >     >
> >     >     >
> >     >     >
> >     >     >
> >     >     >
> >     >     >
> >     >     > _______________________________________________
> >     >     > AstroPy mailing list
> >     >     > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
> >     >     > http://mail.scipy.org/mailman/listinfo/astropy
> >     >     >
> >     >
> >     >     _______________________________________________
> >     >     AstroPy mailing list
> >     >     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
> >     >     http://mail.scipy.org/mailman/listinfo/astropy
> >     >
> >     >
> >     >
> >     >
> >     > --
> >     > Aycha Tammour
> >     > Astronomy PhD Candidate
> >     > University of Western Ontario
> >     >
> >     > _______________________________________________
> >     > AstroPy mailing list
> >     > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     > http://mail.scipy.org/mailman/listinfo/astropy
> >
> >
> > _______________________________________________
> > AstroPy mailing list
> > AstroPy at scipy.org
> > http://mail.scipy.org/mailman/listinfo/astropy
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>



-- 
Aycha Tammour
Astronomy PhD Candidate
University of Western Ontario
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From maik.riechert at arcor.de  Thu Sep 18 17:04:17 2014
From: maik.riechert at arcor.de (Maik Riechert)
Date: Thu, 18 Sep 2014 23:04:17 +0200
Subject: [AstroPy] Bug in wcs_world2pix?
Message-ID: <541B48D1.5060902@arcor.de>

Hi,

I'm having some great trouble currently and am a bit confused too:

wcs = WCS(header)
x,y = wcs.wcs_world2pix(211, -26, 0)
print x,y # 836.316942718 658.26364248
ra,dec = wcs.wcs_pix2world(x, y, 0)
print ra, dec # 31.0 26.0

It seems like world2pix gives me bogus results. I was expecting values
way outside my image area (image size is 4256x2832). Am I doing
something obvious wrong?

The WCS headers can be seen at http://pastebin.com/JrdiL949

Thanks for the help,
Maik


From dklaes at astro.uni-bonn.de  Thu Sep 18 18:50:52 2014
From: dklaes at astro.uni-bonn.de (Dominik Klaes)
Date: Fri, 19 Sep 2014 00:50:52 +0200
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <541B48D1.5060902@arcor.de>
References: <541B48D1.5060902@arcor.de>
Message-ID: <a4fc9ef6-56d4-491c-bb36-1fd8cf4a4537@email.android.com>

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

Hi Maik,

try instead of this

x,y = wcs.wcs_world2pix(211, -26, 0)

this

x,y = wcs.wcs_world2pix([[211, -26]], 0), also in the transformation back. Does this help? I remember that I had a similar problem.

Cheers,

Dominik

On 18. September 2014 23:04:17 MESZ, Maik Riechert <maik.riechert at arcor.de> wrote:
>Hi,
>
>I'm having some great trouble currently and am a bit confused too:
>
>wcs = WCS(header)
>x,y = wcs.wcs_world2pix(211, -26, 0)
>print x,y # 836.316942718 658.26364248
>ra,dec = wcs.wcs_pix2world(x, y, 0)
>print ra, dec # 31.0 26.0
>
>It seems like world2pix gives me bogus results. I was expecting values
>way outside my image area (image size is 4256x2832). Am I doing
>something obvious wrong?
>
>The WCS headers can be seen at http://pastebin.com/JrdiL949
>
>Thanks for the help,
>Maik
>_______________________________________________
>AstroPy mailing list
>AstroPy at scipy.org
>http://mail.scipy.org/mailman/listinfo/astropy
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From mdroe at stsci.edu  Thu Sep 18 20:26:06 2014
From: mdroe at stsci.edu (Michael Droettboom)
Date: Thu, 18 Sep 2014 20:26:06 -0400
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <541B48D1.5060902@arcor.de>
References: <541B48D1.5060902@arcor.de>
Message-ID: <541B781E.1010203@stsci.edu>

The range of ra and dec is (-180, 180) and (-90, 90) respectively.  
(211, -26) is equivalent to (31, 26).

Mike

On 09/18/2014 05:04 PM, Maik Riechert wrote:
> Hi,
>
> I'm having some great trouble currently and am a bit confused too:
>
> wcs = WCS(header)
> x,y = wcs.wcs_world2pix(211, -26, 0)
> print x,y # 836.316942718 658.26364248
> ra,dec = wcs.wcs_pix2world(x, y, 0)
> print ra, dec # 31.0 26.0
>
> It seems like world2pix gives me bogus results. I was expecting values
> way outside my image area (image size is 4256x2832). Am I doing
> something obvious wrong?
>
> The WCS headers can be seen at http://pastebin.com/JrdiL949
>
> Thanks for the help,
> Maik
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy


-- 
Michael Droettboom
Science Software Branch
Space Telescope Science Institute

http://www.droettboom.com



From Alexander.Conley at Colorado.EDU  Thu Sep 18 22:19:01 2014
From: Alexander.Conley at Colorado.EDU (Alexander Joseph Conley)
Date: Thu, 18 Sep 2014 20:19:01 -0600
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <541B781E.1010203@stsci.edu>
References: <541B48D1.5060902@arcor.de> <541B781E.1010203@stsci.edu>
Message-ID: <4CC1FD8F-6F1D-4EFC-8B4E-4695A93C11D1@colorado.edu>

Wouldn?t that end up as -149, -26 it it wrapped at 180?
And how does -26 DEC end up as +26 DEC?  Or am I
completely misunderstanding something about the wrapping
here?

Alex

On Sep 18, 2014, at 6:26 PM, Michael Droettboom <mdroe at stsci.edu> wrote:

> The range of ra and dec is (-180, 180) and (-90, 90) respectively.  
> (211, -26) is equivalent to (31, 26).
> 
> Mike
> 
> On 09/18/2014 05:04 PM, Maik Riechert wrote:
>> Hi,
>> 
>> I'm having some great trouble currently and am a bit confused too:
>> 
>> wcs = WCS(header)
>> x,y = wcs.wcs_world2pix(211, -26, 0)
>> print x,y # 836.316942718 658.26364248
>> ra,dec = wcs.wcs_pix2world(x, y, 0)
>> print ra, dec # 31.0 26.0
>> 
>> It seems like world2pix gives me bogus results. I was expecting values
>> way outside my image area (image size is 4256x2832). Am I doing
>> something obvious wrong?
>> 
>> The WCS headers can be seen at http://pastebin.com/JrdiL949
>> 
>> Thanks for the help,
>> Maik
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
> 
> 
> -- 
> Michael Droettboom
> Science Software Branch
> Space Telescope Science Institute
> 
> http://www.droettboom.com
> 
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy



From maik.riechert at arcor.de  Fri Sep 19 01:53:54 2014
From: maik.riechert at arcor.de (Maik Riechert)
Date: Fri, 19 Sep 2014 07:53:54 +0200
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <a4fc9ef6-56d4-491c-bb36-1fd8cf4a4537@email.android.com>
References: <541B48D1.5060902@arcor.de>
	<a4fc9ef6-56d4-491c-bb36-1fd8cf4a4537@email.android.com>
Message-ID: <541BC4F2.2040404@arcor.de>

Hi Dominik,

Nope, same results.

Cheers
Maik

Am 19.09.2014 00:50, schrieb Dominik Klaes:
> Hi Maik,
> 
> try instead of this
> 
> x,y = wcs.wcs_world2pix(211, -26, 0)
> 
> this
> 
> x,y = wcs.wcs_world2pix([[211, -26]], 0), also in the transformation back. Does this help? I remember that I had a similar problem.
> 
> Cheers,
> 
> Dominik
> 
> On 18. September 2014 23:04:17 MESZ, Maik Riechert <maik.riechert at arcor.de> wrote:
>> Hi,
> 
>> I'm having some great trouble currently and am a bit confused too:
> 
>> wcs = WCS(header)
>> x,y = wcs.wcs_world2pix(211, -26, 0)
>> print x,y # 836.316942718 658.26364248
>> ra,dec = wcs.wcs_pix2world(x, y, 0)
>> print ra, dec # 31.0 26.0
> 
>> It seems like world2pix gives me bogus results. I was expecting values
>> way outside my image area (image size is 4256x2832). Am I doing
>> something obvious wrong?
> 
>> The WCS headers can be seen at http://pastebin.com/JrdiL949
> 
>> Thanks for the help,
>> Maik
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
> 



From thomas.robitaille at gmail.com  Fri Sep 19 03:30:33 2014
From: thomas.robitaille at gmail.com (Thomas Robitaille)
Date: Fri, 19 Sep 2014 09:30:33 +0200
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <541B781E.1010203@stsci.edu>
References: <541B48D1.5060902@arcor.de> <541B781E.1010203@stsci.edu>
Message-ID: <541BDB99.8050505@gmail.com>

I think the coordinates are exactly 180 degrees off - that is, (31, 26)
is the exact antipode of (211, -26). So it seems that there is still an
issue? If the RA got wrapped, it would be (-149, -26).

Cheers,
Tom

Michael Droettboom wrote:
> The range of ra and dec is (-180, 180) and (-90, 90) respectively.  
> (211, -26) is equivalent to (31, 26).
> 
> Mike
> 
> On 09/18/2014 05:04 PM, Maik Riechert wrote:
>> Hi,
>>
>> I'm having some great trouble currently and am a bit confused too:
>>
>> wcs = WCS(header)
>> x,y = wcs.wcs_world2pix(211, -26, 0)
>> print x,y # 836.316942718 658.26364248
>> ra,dec = wcs.wcs_pix2world(x, y, 0)
>> print ra, dec # 31.0 26.0
>>
>> It seems like world2pix gives me bogus results. I was expecting values
>> way outside my image area (image size is 4256x2832). Am I doing
>> something obvious wrong?
>>
>> The WCS headers can be seen at http://pastebin.com/JrdiL949
>>
>> Thanks for the help,
>> Maik
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
> 
> 


From bushouse at stsci.edu  Fri Sep 19 07:47:30 2014
From: bushouse at stsci.edu (Howard Bushouse)
Date: Fri, 19 Sep 2014 11:47:30 +0000
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <541B781E.1010203@stsci.edu>
References: <541B48D1.5060902@arcor.de> <541B781E.1010203@stsci.edu>
Message-ID: <517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>

Huh. But that?s not how astronomers measure RA and Dec, even when translated to degrees. If I?ve got an object with an RA of 17:45:00.0 (hh:mm:ss.w) the RA in degrees is 266.25. We *never* use a negative RA. Instead of a range of -180 to 180, we use 0 to 360. Dec is the only one that ever goes negative (-90 to +90, as you indicated).

-hb

On Sep 18, 2014, at 8:26 PM, Michael Droettboom <mdroe at stsci.edu> wrote:

> The range of ra and dec is (-180, 180) and (-90, 90) respectively.  
> (211, -26) is equivalent to (31, 26).
> 
> Mike
> 
> On 09/18/2014 05:04 PM, Maik Riechert wrote:
>> Hi,
>> 
>> I'm having some great trouble currently and am a bit confused too:
>> 
>> wcs = WCS(header)
>> x,y = wcs.wcs_world2pix(211, -26, 0)
>> print x,y # 836.316942718 658.26364248
>> ra,dec = wcs.wcs_pix2world(x, y, 0)
>> print ra, dec # 31.0 26.0
>> 
>> It seems like world2pix gives me bogus results. I was expecting values
>> way outside my image area (image size is 4256x2832). Am I doing
>> something obvious wrong?
>> 
>> The WCS headers can be seen at http://pastebin.com/JrdiL949
>> 
>> Thanks for the help,
>> Maik
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
> 
> 
> -- 
> Michael Droettboom
> Science Software Branch
> Space Telescope Science Institute
> 
> http://www.droettboom.com
> 
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy



From bgarwood at nrao.edu  Fri Sep 19 07:58:00 2014
From: bgarwood at nrao.edu (Bob Garwood)
Date: Fri, 19 Sep 2014 07:58:00 -0400
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>
References: <541B48D1.5060902@arcor.de> <541B781E.1010203@stsci.edu>
	<517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>
Message-ID: <b944306b-aeb5-4d57-9aec-23dc60d39e74@email.android.com>

I suspect what's going on here has to do with the specific CD matrix, which includes rotation.  I think because of that rotation the world coordinate actually maps back in to the grid at the antipode.  I haven't checked this by hand to see if that's the case.

Bob

On September 19, 2014 7:47:30 AM EDT, Howard Bushouse <bushouse at stsci.edu> wrote:
>Huh. But that?s not how astronomers measure RA and Dec, even when
>translated to degrees. If I?ve got an object with an RA of 17:45:00.0
>(hh:mm:ss.w) the RA in degrees is 266.25. We *never* use a negative RA.
>Instead of a range of -180 to 180, we use 0 to 360. Dec is the only one
>that ever goes negative (-90 to +90, as you indicated).
>
>-hb
>
>On Sep 18, 2014, at 8:26 PM, Michael Droettboom <mdroe at stsci.edu>
>wrote:
>
>> The range of ra and dec is (-180, 180) and (-90, 90) respectively.  
>> (211, -26) is equivalent to (31, 26).
>> 
>> Mike
>> 
>> On 09/18/2014 05:04 PM, Maik Riechert wrote:
>>> Hi,
>>> 
>>> I'm having some great trouble currently and am a bit confused too:
>>> 
>>> wcs = WCS(header)
>>> x,y = wcs.wcs_world2pix(211, -26, 0)
>>> print x,y # 836.316942718 658.26364248
>>> ra,dec = wcs.wcs_pix2world(x, y, 0)
>>> print ra, dec # 31.0 26.0
>>> 
>>> It seems like world2pix gives me bogus results. I was expecting
>values
>>> way outside my image area (image size is 4256x2832). Am I doing
>>> something obvious wrong?
>>> 
>>> The WCS headers can be seen at http://pastebin.com/JrdiL949
>>> 
>>> Thanks for the help,
>>> Maik
>>> _______________________________________________
>>> AstroPy mailing list
>>> AstroPy at scipy.org
>>> http://mail.scipy.org/mailman/listinfo/astropy
>> 
>> 
>> -- 
>> Michael Droettboom
>> Science Software Branch
>> Space Telescope Science Institute
>> 
>> http://www.droettboom.com
>> 
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
>
>_______________________________________________
>AstroPy mailing list
>AstroPy at scipy.org
>http://mail.scipy.org/mailman/listinfo/astropy
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From d.berry at jach.hawaii.edu  Fri Sep 19 08:14:33 2014
From: d.berry at jach.hawaii.edu (David Berry)
Date: Fri, 19 Sep 2014 13:14:33 +0100
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <b944306b-aeb5-4d57-9aec-23dc60d39e74@email.android.com>
References: <541B48D1.5060902@arcor.de> <541B781E.1010203@stsci.edu>
	<517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>
	<b944306b-aeb5-4d57-9aec-23dc60d39e74@email.android.com>
Message-ID: <CAALafn6OB=foNWdnRYKAa-P9ZExe0DXWbby-gA4r1G_DJdasQA@mail.gmail.com>

Am I missing something? This is a TAN projection centred on CRVAL1=16,
CRVAL2=23. Since it is a TAN projection, the projection plane only
includes half the sky - i.e. the hemisphere centred on (16,23). But
the test point (211,-26) is not contained within this hemisphere and
so is not included in the TAN projection plane. In other words, no
pixel has the coordinates RA=211 Dec=-26, and so the results of  using
wcs.wcs_world2pix should be NaN, or "invalid", or something.

Unless I'm missing something...

David


On 19 September 2014 12:58, Bob Garwood <bgarwood at nrao.edu> wrote:
> I suspect what's going on here has to do with the specific CD matrix, which
> includes rotation. I think because of that rotation the world coordinate
> actually maps back in to the grid at the antipode. I haven't checked this by
> hand to see if that's the case.
>
> Bob
>
> On September 19, 2014 7:47:30 AM EDT, Howard Bushouse <bushouse at stsci.edu>
> wrote:
>>
>> Huh. But that?s not how astronomers measure RA and Dec, even when
>> translated to degrees. If I?ve got an object with an RA of 17:45:00.0
>> (hh:mm:ss.w) the RA in degrees is 266.25. We *never* use a negative RA.
>> Instead of a range of -180 to 180, we use 0 to 360. Dec is the only one that
>> ever goes negative (-90 to +90, as you indicated).
>>
>> -hb
>>
>> On Sep 18, 2014, at 8:26 PM, Michael Droettboom <mdroe at stsci.edu> wrote:
>>
>>>  The range of ra and dec is (-180, 180) and (-90, 90) respectively.
>>>  (211, -26) is equivalent to (31, 26).
>>>
>>>  Mike
>>>
>>>  On 09/18/2014 05:04 PM, Maik Riechert wrote:
>>>>
>>>>  Hi,
>>>>
>>>>  I'm having some great trouble currently and am a bit confused to!
>>>>  o:
>>>>
>>>>
>>>>  wcs = WCS(header)
>>>>  x,y = wcs.wcs_world2pix(211, -26, 0)
>>>>  print x,y # 836.316942718 658.26364248
>>>>  ra,dec = wcs.wcs_pix2world(x, y, 0)
>>>>  print ra, dec # 31.0 26.0
>>>>
>>>>  It seems like world2pix gives me bogus results. I was expecting values
>>>>  way outside my image area (image size is 4256x2832). Am I doing
>>>>  something obvious wrong?
>>>>
>>>>  The WCS headers can be seen at http://pastebin.com/JrdiL949
>>>>
>>>>  Thanks for the help,
>>>>  Maik
>>>> ________________________________
>>>>
>>>>  AstroPy mailing list
>>>>  AstroPy at scipy.org
>>>>  http://mail.scipy.org/mailman/listinfo/astropy
>>>
>>>
>>>
>>>  --
>>>  Michael Droettboom
>>>  Science Software Branch
>>>  Space Telescope Science Institute
>>>
>>>  http://www.droettboom.com
>>>
>>> ________________________________
>>>
>>>  AstroPy mailing list
>>>  AstroPy at scipy.or!
>>>  g
>>>
>>> http://mail.scipy.org/mailman/listinfo/astropy
>>
>>
>> ________________________________
>>
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>


From mdroe at stsci.edu  Fri Sep 19 08:18:54 2014
From: mdroe at stsci.edu (Michael Droettboom)
Date: Fri, 19 Sep 2014 08:18:54 -0400
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>
References: <541B48D1.5060902@arcor.de> <541B781E.1010203@stsci.edu>
	<517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>
Message-ID: <541C1F2E.2040408@stsci.edu>

Sorry for the confusion -- I wrote this based on what the wcslib code 
does, forgetting that it primarily works in lon, lat internally, before 
converting to ra, dec at a later stage.

Mike

On 09/19/2014 07:47 AM, Howard Bushouse wrote:
> Huh. But that?s not how astronomers measure RA and Dec, even when translated to degrees. If I?ve got an object with an RA of 17:45:00.0 (hh:mm:ss.w) the RA in degrees is 266.25. We *never* use a negative RA. Instead of a range of -180 to 180, we use 0 to 360. Dec is the only one that ever goes negative (-90 to +90, as you indicated).
>
> -hb
>
> On Sep 18, 2014, at 8:26 PM, Michael Droettboom <mdroe at stsci.edu> wrote:
>
>> The range of ra and dec is (-180, 180) and (-90, 90) respectively.
>> (211, -26) is equivalent to (31, 26).
>>
>> Mike
>>
>> On 09/18/2014 05:04 PM, Maik Riechert wrote:
>>> Hi,
>>>
>>> I'm having some great trouble currently and am a bit confused too:
>>>
>>> wcs = WCS(header)
>>> x,y = wcs.wcs_world2pix(211, -26, 0)
>>> print x,y # 836.316942718 658.26364248
>>> ra,dec = wcs.wcs_pix2world(x, y, 0)
>>> print ra, dec # 31.0 26.0
>>>
>>> It seems like world2pix gives me bogus results. I was expecting values
>>> way outside my image area (image size is 4256x2832). Am I doing
>>> something obvious wrong?
>>>
>>> The WCS headers can be seen at http://pastebin.com/JrdiL949
>>>
>>> Thanks for the help,
>>> Maik
>>> _______________________________________________
>>> AstroPy mailing list
>>> AstroPy at scipy.org
>>> http://mail.scipy.org/mailman/listinfo/astropy
>>
>> -- 
>> Michael Droettboom
>> Science Software Branch
>> Space Telescope Science Institute
>>
>> http://www.droettboom.com
>>
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy


-- 
Michael Droettboom
Science Software Branch
Space Telescope Science Institute

http://www.droettboom.com



From mdroe at stsci.edu  Fri Sep 19 08:23:30 2014
From: mdroe at stsci.edu (Michael Droettboom)
Date: Fri, 19 Sep 2014 08:23:30 -0400
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <CAALafn6OB=foNWdnRYKAa-P9ZExe0DXWbby-gA4r1G_DJdasQA@mail.gmail.com>
References: <541B48D1.5060902@arcor.de>
	<541B781E.1010203@stsci.edu>	<517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>	<b944306b-aeb5-4d57-9aec-23dc60d39e74@email.android.com>
	<CAALafn6OB=foNWdnRYKAa-P9ZExe0DXWbby-gA4r1G_DJdasQA@mail.gmail.com>
Message-ID: <541C2042.1070302@stsci.edu>

I've brought this to Mark Calabretta's attention -- he may have an idea.

Mike

On 09/19/2014 08:14 AM, David Berry wrote:
> Am I missing something? This is a TAN projection centred on CRVAL1=16,
> CRVAL2=23. Since it is a TAN projection, the projection plane only
> includes half the sky - i.e. the hemisphere centred on (16,23). But
> the test point (211,-26) is not contained within this hemisphere and
> so is not included in the TAN projection plane. In other words, no
> pixel has the coordinates RA=211 Dec=-26, and so the results of  using
> wcs.wcs_world2pix should be NaN, or "invalid", or something.
>
> Unless I'm missing something...
>
> David
>
>
> On 19 September 2014 12:58, Bob Garwood <bgarwood at nrao.edu> wrote:
>> I suspect what's going on here has to do with the specific CD matrix, which
>> includes rotation. I think because of that rotation the world coordinate
>> actually maps back in to the grid at the antipode. I haven't checked this by
>> hand to see if that's the case.
>>
>> Bob
>>
>> On September 19, 2014 7:47:30 AM EDT, Howard Bushouse <bushouse at stsci.edu>
>> wrote:
>>> Huh. But that?s not how astronomers measure RA and Dec, even when
>>> translated to degrees. If I?ve got an object with an RA of 17:45:00.0
>>> (hh:mm:ss.w) the RA in degrees is 266.25. We *never* use a negative RA.
>>> Instead of a range of -180 to 180, we use 0 to 360. Dec is the only one that
>>> ever goes negative (-90 to +90, as you indicated).
>>>
>>> -hb
>>>
>>> On Sep 18, 2014, at 8:26 PM, Michael Droettboom <mdroe at stsci.edu> wrote:
>>>
>>>>   The range of ra and dec is (-180, 180) and (-90, 90) respectively.
>>>>   (211, -26) is equivalent to (31, 26).
>>>>
>>>>   Mike
>>>>
>>>>   On 09/18/2014 05:04 PM, Maik Riechert wrote:
>>>>>   Hi,
>>>>>
>>>>>   I'm having some great trouble currently and am a bit confused to!
>>>>>   o:
>>>>>
>>>>>
>>>>>   wcs = WCS(header)
>>>>>   x,y = wcs.wcs_world2pix(211, -26, 0)
>>>>>   print x,y # 836.316942718 658.26364248
>>>>>   ra,dec = wcs.wcs_pix2world(x, y, 0)
>>>>>   print ra, dec # 31.0 26.0
>>>>>
>>>>>   It seems like world2pix gives me bogus results. I was expecting values
>>>>>   way outside my image area (image size is 4256x2832). Am I doing
>>>>>   something obvious wrong?
>>>>>
>>>>>   The WCS headers can be seen at http://pastebin.com/JrdiL949
>>>>>
>>>>>   Thanks for the help,
>>>>>   Maik
>>>>> ________________________________
>>>>>
>>>>>   AstroPy mailing list
>>>>>   AstroPy at scipy.org
>>>>>   http://mail.scipy.org/mailman/listinfo/astropy
>>>>
>>>>
>>>>   --
>>>>   Michael Droettboom
>>>>   Science Software Branch
>>>>   Space Telescope Science Institute
>>>>
>>>>   http://www.droettboom.com
>>>>
>>>> ________________________________
>>>>
>>>>   AstroPy mailing list
>>>>   AstroPy at scipy.or!
>>>>   g
>>>>
>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>
>>> ________________________________
>>>
>>> AstroPy mailing list
>>> AstroPy at scipy.org
>>> http://mail.scipy.org/mailman/listinfo/astropy
>>
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
>>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy


-- 
Michael Droettboom
Science Software Branch
Space Telescope Science Institute

http://www.droettboom.com



From d.berry at jach.hawaii.edu  Fri Sep 19 09:13:05 2014
From: d.berry at jach.hawaii.edu (David Berry)
Date: Fri, 19 Sep 2014 14:13:05 +0100
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <541C2042.1070302@stsci.edu>
References: <541B48D1.5060902@arcor.de> <541B781E.1010203@stsci.edu>
	<517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>
	<b944306b-aeb5-4d57-9aec-23dc60d39e74@email.android.com>
	<CAALafn6OB=foNWdnRYKAa-P9ZExe0DXWbby-gA4r1G_DJdasQA@mail.gmail.com>
	<541C2042.1070302@stsci.edu>
Message-ID: <CAALafn4HHTppvgD5m_SDUtFsch+nSbDG0RwqY7nHcTnEvbk_jQ@mail.gmail.com>

On 19 September 2014 13:23, Michael Droettboom <mdroe at stsci.edu> wrote:
> I've brought this to Mark Calabretta's attention -- he may have an idea.

wcslib provides an option to switch this sort of range checking on or
off. With pyast, I take the attitude that the answer to the question
(in this case)  "what pixel has coords RA=211 Dec=-26" is "no pixel
has those coords", and so pyast will always return "NaN" values in
such circumstances. To return apparently usable values which are in
fact wrong is just asking for problems in my opinion.

David


From thomas.robitaille at gmail.com  Fri Sep 19 09:14:34 2014
From: thomas.robitaille at gmail.com (Thomas Robitaille)
Date: Fri, 19 Sep 2014 15:14:34 +0200
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <CAALafn6OB=foNWdnRYKAa-P9ZExe0DXWbby-gA4r1G_DJdasQA@mail.gmail.com>
References: <541B48D1.5060902@arcor.de> <541B781E.1010203@stsci.edu>
	<517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>
	<b944306b-aeb5-4d57-9aec-23dc60d39e74@email.android.com>
	<CAALafn6OB=foNWdnRYKAa-P9ZExe0DXWbby-gA4r1G_DJdasQA@mail.gmail.com>
Message-ID: <CAGMHX_1AJ_Vr+omJpkkOGrQwrBOL29pbocrv4EuudYp+u=kHdw@mail.gmail.com>

Ah of course, this is indeed what is going on here! I agree that it's
worth thinking about whether cases like this should return an error.
In the past (in WCSAxes) I've simply checked if the coordinate
round-trips in order to determine if it's in the observational plane,
but it may be more sensible to simply return NaN.

Cheers,
Tom

On 19 September 2014 14:14, David Berry <d.berry at jach.hawaii.edu> wrote:
> Am I missing something? This is a TAN projection centred on CRVAL1=16,
> CRVAL2=23. Since it is a TAN projection, the projection plane only
> includes half the sky - i.e. the hemisphere centred on (16,23). But
> the test point (211,-26) is not contained within this hemisphere and
> so is not included in the TAN projection plane. In other words, no
> pixel has the coordinates RA=211 Dec=-26, and so the results of  using
> wcs.wcs_world2pix should be NaN, or "invalid", or something.
>
> Unless I'm missing something...
>
> David
>
>
> On 19 September 2014 12:58, Bob Garwood <bgarwood at nrao.edu> wrote:
>> I suspect what's going on here has to do with the specific CD matrix, which
>> includes rotation. I think because of that rotation the world coordinate
>> actually maps back in to the grid at the antipode. I haven't checked this by
>> hand to see if that's the case.
>>
>> Bob
>>
>> On September 19, 2014 7:47:30 AM EDT, Howard Bushouse <bushouse at stsci.edu>
>> wrote:
>>>
>>> Huh. But that?s not how astronomers measure RA and Dec, even when
>>> translated to degrees. If I?ve got an object with an RA of 17:45:00.0
>>> (hh:mm:ss.w) the RA in degrees is 266.25. We *never* use a negative RA.
>>> Instead of a range of -180 to 180, we use 0 to 360. Dec is the only one that
>>> ever goes negative (-90 to +90, as you indicated).
>>>
>>> -hb
>>>
>>> On Sep 18, 2014, at 8:26 PM, Michael Droettboom <mdroe at stsci.edu> wrote:
>>>
>>>>  The range of ra and dec is (-180, 180) and (-90, 90) respectively.
>>>>  (211, -26) is equivalent to (31, 26).
>>>>
>>>>  Mike
>>>>
>>>>  On 09/18/2014 05:04 PM, Maik Riechert wrote:
>>>>>
>>>>>  Hi,
>>>>>
>>>>>  I'm having some great trouble currently and am a bit confused to!
>>>>>  o:
>>>>>
>>>>>
>>>>>  wcs = WCS(header)
>>>>>  x,y = wcs.wcs_world2pix(211, -26, 0)
>>>>>  print x,y # 836.316942718 658.26364248
>>>>>  ra,dec = wcs.wcs_pix2world(x, y, 0)
>>>>>  print ra, dec # 31.0 26.0
>>>>>
>>>>>  It seems like world2pix gives me bogus results. I was expecting values
>>>>>  way outside my image area (image size is 4256x2832). Am I doing
>>>>>  something obvious wrong?
>>>>>
>>>>>  The WCS headers can be seen at http://pastebin.com/JrdiL949
>>>>>
>>>>>  Thanks for the help,
>>>>>  Maik
>>>>> ________________________________
>>>>>
>>>>>  AstroPy mailing list
>>>>>  AstroPy at scipy.org
>>>>>  http://mail.scipy.org/mailman/listinfo/astropy
>>>>
>>>>
>>>>
>>>>  --
>>>>  Michael Droettboom
>>>>  Science Software Branch
>>>>  Space Telescope Science Institute
>>>>
>>>>  http://www.droettboom.com
>>>>
>>>> ________________________________
>>>>
>>>>  AstroPy mailing list
>>>>  AstroPy at scipy.or!
>>>>  g
>>>>
>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>
>>>
>>> ________________________________
>>>
>>> AstroPy mailing list
>>> AstroPy at scipy.org
>>> http://mail.scipy.org/mailman/listinfo/astropy
>>
>>
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
>>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy


From bgarwood at nrao.edu  Fri Sep 19 09:29:56 2014
From: bgarwood at nrao.edu (Bob Garwood)
Date: Fri, 19 Sep 2014 09:29:56 -0400
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <CAALafn6OB=foNWdnRYKAa-P9ZExe0DXWbby-gA4r1G_DJdasQA@mail.gmail.com>
References: <541B48D1.5060902@arcor.de> <541B781E.1010203@stsci.edu>
	<517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>
	<b944306b-aeb5-4d57-9aec-23dc60d39e74@email.android.com>
	<CAALafn6OB=foNWdnRYKAa-P9ZExe0DXWbby-gA4r1G_DJdasQA@mail.gmail.com>
Message-ID: <9429ddb2-5d26-4e11-b63c-5f89ebc10917@email.android.com>

D 'oh.  Of course.

On September 19, 2014 8:14:33 AM EDT, David Berry <d.berry at jach.hawaii.edu> wrote:
>Am I missing something? This is a TAN projection centred on CRVAL1=16,
>CRVAL2=23. Since it is a TAN projection, the projection plane only
>includes half the sky - i.e. the hemisphere centred on (16,23). But
>the test point (211,-26) is not contained within this hemisphere and
>so is not included in the TAN projection plane. In other words, no
>pixel has the coordinates RA=211 Dec=-26, and so the results of  using
>wcs.wcs_world2pix should be NaN, or "invalid", or something.
>
>Unless I'm missing something...
>
>David
>
>
>On 19 September 2014 12:58, Bob Garwood <bgarwood at nrao.edu> wrote:
>> I suspect what's going on here has to do with the specific CD matrix,
>which
>> includes rotation. I think because of that rotation the world
>coordinate
>> actually maps back in to the grid at the antipode. I haven't checked
>this by
>> hand to see if that's the case.
>>
>> Bob
>>
>> On September 19, 2014 7:47:30 AM EDT, Howard Bushouse
><bushouse at stsci.edu>
>> wrote:
>>>
>>> Huh. But that?s not how astronomers measure RA and Dec, even when
>>> translated to degrees. If I?ve got an object with an RA of
>17:45:00.0
>>> (hh:mm:ss.w) the RA in degrees is 266.25. We *never* use a negative
>RA.
>>> Instead of a range of -180 to 180, we use 0 to 360. Dec is the only
>one that
>>> ever goes negative (-90 to +90, as you indicated).
>>>
>>> -hb
>>>
>>> On Sep 18, 2014, at 8:26 PM, Michael Droettboom <mdroe at stsci.edu>
>wrote:
>>>
>>>>  The range of ra and dec is (-180, 180) and (-90, 90) respectively.
>>>>  (211, -26) is equivalent to (31, 26).
>>>>
>>>>  Mike
>>>>
>>>>  On 09/18/2014 05:04 PM, Maik Riechert wrote:
>>>>>
>>>>>  Hi,
>>>>>
>>>>>  I'm having some great trouble currently and am a bit confused to!
>>>>>  o:
>>>>>
>>>>>
>>>>>  wcs = WCS(header)
>>>>>  x,y = wcs.wcs_world2pix(211, -26, 0)
>>>>>  print x,y # 836.316942718 658.26364248
>>>>>  ra,dec = wcs.wcs_pix2world(x, y, 0)
>>>>>  print ra, dec # 31.0 26.0
>>>>>
>>>>>  It seems like world2pix gives me bogus results. I was expecting
>values
>>>>>  way outside my image area (image size is 4256x2832). Am I doing
>>>>>  something obvious wrong?
>>>>>
>>>>>  The WCS headers can be seen at http://pastebin.com/JrdiL949
>>>>>
>>>>>  Thanks for the help,
>>>>>  Maik
>>>>> ________________________________
>>>>>
>>>>>  AstroPy mailing list
>>>>>  AstroPy at scipy.org
>>>>>  http://mail.scipy.org/mailman/listinfo/astropy
>>>>
>>>>
>>>>
>>>>  --
>>>>  Michael Droettboom
>>>>  Science Software Branch
>>>>  Space Telescope Science Institute
>>>>
>>>>  http://www.droettboom.com
>>>>
>>>> ________________________________
>>>>
>>>>  AstroPy mailing list
>>>>  AstroPy at scipy.or!
>>>>  g
>>>>
>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>
>>>
>>> ________________________________
>>>
>>> AstroPy mailing list
>>> AstroPy at scipy.org
>>> http://mail.scipy.org/mailman/listinfo/astropy
>>
>>
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
>>
>_______________________________________________
>AstroPy mailing list
>AstroPy at scipy.org
>http://mail.scipy.org/mailman/listinfo/astropy
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From mdroe at stsci.edu  Fri Sep 19 10:01:00 2014
From: mdroe at stsci.edu (Michael Droettboom)
Date: Fri, 19 Sep 2014 10:01:00 -0400
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <CAALafn4HHTppvgD5m_SDUtFsch+nSbDG0RwqY7nHcTnEvbk_jQ@mail.gmail.com>
References: <541B48D1.5060902@arcor.de>
	<541B781E.1010203@stsci.edu>	<517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>	<b944306b-aeb5-4d57-9aec-23dc60d39e74@email.android.com>	<CAALafn6OB=foNWdnRYKAa-P9ZExe0DXWbby-gA4r1G_DJdasQA@mail.gmail.com>	<541C2042.1070302@stsci.edu>
	<CAALafn4HHTppvgD5m_SDUtFsch+nSbDG0RwqY7nHcTnEvbk_jQ@mail.gmail.com>
Message-ID: <541C371C.7040201@stsci.edu>

On 09/19/2014 09:13 AM, David Berry wrote:
> On 19 September 2014 13:23, Michael Droettboom <mdroe at stsci.edu> wrote:
>> I've brought this to Mark Calabretta's attention -- he may have an idea.
> wcslib provides an option to switch this sort of range checking on or
> off. With pyast, I take the attitude that the answer to the question
> (in this case)  "what pixel has coords RA=211 Dec=-26" is "no pixel
> has those coords", and so pyast will always return "NaN" values in
> such circumstances. To return apparently usable values which are in
> fact wrong is just asking for problems in my opinion.
Yes, but the WCS range checking only happens for a TAN projection in the 
pixel-to-sphere direction.  Not sure why that is.  In this particular 
case, it's "garbage in", but "reasonable values out" from s2p, and then 
p2s can't know to complain about it.  That might be something to improve 
there.

Mike

-- 
Michael Droettboom
Science Software Branch
Space Telescope Science Institute

http://www.droettboom.com



From d.berry at jach.hawaii.edu  Fri Sep 19 10:09:44 2014
From: d.berry at jach.hawaii.edu (David Berry)
Date: Fri, 19 Sep 2014 15:09:44 +0100
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <541C371C.7040201@stsci.edu>
References: <541B48D1.5060902@arcor.de> <541B781E.1010203@stsci.edu>
	<517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>
	<b944306b-aeb5-4d57-9aec-23dc60d39e74@email.android.com>
	<CAALafn6OB=foNWdnRYKAa-P9ZExe0DXWbby-gA4r1G_DJdasQA@mail.gmail.com>
	<541C2042.1070302@stsci.edu>
	<CAALafn4HHTppvgD5m_SDUtFsch+nSbDG0RwqY7nHcTnEvbk_jQ@mail.gmail.com>
	<541C371C.7040201@stsci.edu>
Message-ID: <CAALafn6-NpB-4wgtDBE_NF6aypwoqdqzjyVQXEXKSVoXDj_+1Q@mail.gmail.com>

On 19 September 2014 15:01, Michael Droettboom <mdroe at stsci.edu> wrote:
> On 09/19/2014 09:13 AM, David Berry wrote:
>> On 19 September 2014 13:23, Michael Droettboom <mdroe at stsci.edu> wrote:
>>> I've brought this to Mark Calabretta's attention -- he may have an idea.
>> wcslib provides an option to switch this sort of range checking on or
>> off. With pyast, I take the attitude that the answer to the question
>> (in this case)  "what pixel has coords RA=211 Dec=-26" is "no pixel
>> has those coords", and so pyast will always return "NaN" values in
>> such circumstances. To return apparently usable values which are in
>> fact wrong is just asking for problems in my opinion.

> Yes, but the WCS range checking only happens for a TAN projection in the
> pixel-to-sphere direction.  Not sure why that is.  In this particular
> case, it's "garbage in", but "reasonable values out" from s2p, and then
> p2s can't know to complain about it.  That might be something to improve
> there.

The docs for the wcsbchk function within wcslib says that if the
"bounds" value is odd, then strict bounds checking is performed for
the spherical-to-Cartesian (s2x) transformation for a TAN projection.

David


From mdroe at stsci.edu  Fri Sep 19 10:17:03 2014
From: mdroe at stsci.edu (Michael Droettboom)
Date: Fri, 19 Sep 2014 10:17:03 -0400
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <CAALafn6-NpB-4wgtDBE_NF6aypwoqdqzjyVQXEXKSVoXDj_+1Q@mail.gmail.com>
References: <541B48D1.5060902@arcor.de>
	<541B781E.1010203@stsci.edu>	<517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>	<b944306b-aeb5-4d57-9aec-23dc60d39e74@email.android.com>	<CAALafn6OB=foNWdnRYKAa-P9ZExe0DXWbby-gA4r1G_DJdasQA@mail.gmail.com>	<541C2042.1070302@stsci.edu>	<CAALafn4HHTppvgD5m_SDUtFsch+nSbDG0RwqY7nHcTnEvbk_jQ@mail.gmail.com>	<541C371C.7040201@stsci.edu>
	<CAALafn6-NpB-4wgtDBE_NF6aypwoqdqzjyVQXEXKSVoXDj_+1Q@mail.gmail.com>
Message-ID: <541C3ADF.6060400@stsci.edu>

On 09/19/2014 10:09 AM, David Berry wrote:
> On 19 September 2014 15:01, Michael Droettboom <mdroe at stsci.edu> wrote:
>> On 09/19/2014 09:13 AM, David Berry wrote:
>>> On 19 September 2014 13:23, Michael Droettboom <mdroe at stsci.edu> wrote:
>>>> I've brought this to Mark Calabretta's attention -- he may have an idea.
>>> wcslib provides an option to switch this sort of range checking on or
>>> off. With pyast, I take the attitude that the answer to the question
>>> (in this case)  "what pixel has coords RA=211 Dec=-26" is "no pixel
>>> has those coords", and so pyast will always return "NaN" values in
>>> such circumstances. To return apparently usable values which are in
>>> fact wrong is just asking for problems in my opinion.
>> Yes, but the WCS range checking only happens for a TAN projection in the
>> pixel-to-sphere direction.  Not sure why that is.  In this particular
>> case, it's "garbage in", but "reasonable values out" from s2p, and then
>> p2s can't know to complain about it.  That might be something to improve
>> there.
> The docs for the wcsbchk function within wcslib says that if the
> "bounds" value is odd, then strict bounds checking is performed for
> the spherical-to-Cartesian (s2x) transformation for a TAN projection.
>
So it does.  Not enough coffee today.  Sorry about that.

Mike

-- 
Michael Droettboom
Science Software Branch
Space Telescope Science Institute

http://www.droettboom.com



From maik.riechert at arcor.de  Fri Sep 19 10:57:14 2014
From: maik.riechert at arcor.de (Maik Riechert)
Date: Fri, 19 Sep 2014 16:57:14 +0200
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <CAGMHX_1AJ_Vr+omJpkkOGrQwrBOL29pbocrv4EuudYp+u=kHdw@mail.gmail.com>
References: <541B48D1.5060902@arcor.de>
	<541B781E.1010203@stsci.edu>	<517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>	<b944306b-aeb5-4d57-9aec-23dc60d39e74@email.android.com>	<CAALafn6OB=foNWdnRYKAa-P9ZExe0DXWbby-gA4r1G_DJdasQA@mail.gmail.com>
	<CAGMHX_1AJ_Vr+omJpkkOGrQwrBOL29pbocrv4EuudYp+u=kHdw@mail.gmail.com>
Message-ID: <541C444A.3090900@arcor.de>

Just to add some context of what I'm doing. I got the star constellation 
data from Marshall Perrin the other day on this list. And now I'm trying 
to draw these constellations onto an image using WCS data. That means, 
for each constellation, I convert the RA,DEC points to pixel coordinates 
using wcs_world2pix, then I check whether all points are outside the 
image bounds (in that case I skip drawing it), if they are partly or all 
inside, then I draw the constellation.

So yes, I think the best way would be to return NaN in these cases. 
Otherwise I wouldn't know how to easily filter out those wrong points.

Cheers
Maik


On 19/09/14 15:14, Thomas Robitaille wrote:
> Ah of course, this is indeed what is going on here! I agree that it's
> worth thinking about whether cases like this should return an error.
> In the past (in WCSAxes) I've simply checked if the coordinate
> round-trips in order to determine if it's in the observational plane,
> but it may be more sensible to simply return NaN.
>
> Cheers,
> Tom
>
> On 19 September 2014 14:14, David Berry <d.berry at jach.hawaii.edu> wrote:
>> Am I missing something? This is a TAN projection centred on CRVAL1,
>> CRVAL2#. Since it is a TAN projection, the projection plane only
>> includes half the sky - i.e. the hemisphere centred on (16,23). But
>> the test point (211,-26) is not contained within this hemisphere and
>> so is not included in the TAN projection plane. In other words, no
>> pixel has the coordinates RA!1 Dec=-26, and so the results of  using
>> wcs.wcs_world2pix should be NaN, or "invalid", or something.
>>
>> Unless I'm missing something...
>>
>> David
>>
>>
>> On 19 September 2014 12:58, Bob Garwood <bgarwood at nrao.edu> wrote:
>>> I suspect what's going on here has to do with the specific CD matrix, which
>>> includes rotation. I think because of that rotation the world coordinate
>>> actually maps back in to the grid at the antipode. I haven't checked this by
>>> hand to see if that's the case.
>>>
>>> Bob
>>>
>>> On September 19, 2014 7:47:30 AM EDT, Howard Bushouse <bushouse at stsci.edu>
>>> wrote:
>>>> Huh. But that?s not how astronomers measure RA and Dec, even when
>>>> translated to degrees. If I?ve got an object with an RA of 17:45:00.0
>>>> (hh:mm:ss.w) the RA in degrees is 266.25. We *never* use a negative RA.
>>>> Instead of a range of -180 to 180, we use 0 to 360. Dec is the only one that
>>>> ever goes negative (-90 to +90, as you indicated).
>>>>
>>>> -hb
>>>>
>>>> On Sep 18, 2014, at 8:26 PM, Michael Droettboom <mdroe at stsci.edu> wrote:
>>>>
>>>>>   The range of ra and dec is (-180, 180) and (-90, 90) respectively.
>>>>>   (211, -26) is equivalent to (31, 26).
>>>>>
>>>>>   Mike
>>>>>
>>>>>   On 09/18/2014 05:04 PM, Maik Riechert wrote:
>>>>>>   Hi,
>>>>>>
>>>>>>   I'm having some great trouble currently and am a bit confused to!
>>>>>>   o:
>>>>>>
>>>>>>
>>>>>>   wcs =CS(header)
>>>>>>   x,y =cs.wcs_world2pix(211, -26, 0)
>>>>>>   print x,y # 836.316942718 658.26364248
>>>>>>   ra,dec =cs.wcs_pix2world(x, y, 0)
>>>>>>   print ra, dec # 31.0 26.0
>>>>>>
>>>>>>   It seems like world2pix gives me bogus results. I was expecting values
>>>>>>   way outside my image area (image size is 4256x2832). Am I doing
>>>>>>   something obvious wrong?
>>>>>>
>>>>>>   The WCS headers can be seen at http://pastebin.com/JrdiL949
>>>>>>
>>>>>>   Thanks for the help,
>>>>>>   Maik
>>>>>> ________________________________
>>>>>>
>>>>>>   AstroPy mailing list
>>>>>>   AstroPy at scipy.org
>>>>>>   http://mail.scipy.org/mailman/listinfo/astropy
>>>>>
>>>>>
>>>>>   --
>>>>>   Michael Droettboom
>>>>>   Science Software Branch
>>>>>   Space Telescope Science Institute
>>>>>
>>>>>   http://www.droettboom.com
>>>>>
>>>>> ________________________________
>>>>>
>>>>>   AstroPy mailing list
>>>>>   AstroPy at scipy.or!
>>>>>   g
>>>>>
>>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>>
>>>> ________________________________
>>>>
>>>> AstroPy mailing list
>>>> AstroPy at scipy.org
>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>
>>> _______________________________________________
>>> AstroPy mailing list
>>> AstroPy at scipy.org
>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy


From thomas.robitaille at gmail.com  Fri Sep 19 10:58:53 2014
From: thomas.robitaille at gmail.com (Thomas Robitaille)
Date: Fri, 19 Sep 2014 16:58:53 +0200
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <541C444A.3090900@arcor.de>
References: <541B48D1.5060902@arcor.de>
	<541B781E.1010203@stsci.edu>	<517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>	<b944306b-aeb5-4d57-9aec-23dc60d39e74@email.android.com>	<CAALafn6OB=foNWdnRYKAa-P9ZExe0DXWbby-gA4r1G_DJdasQA@mail.gmail.com>
	<CAGMHX_1AJ_Vr+omJpkkOGrQwrBOL29pbocrv4EuudYp+u=kHdw@mail.gmail.com>
	<541C444A.3090900@arcor.de>
Message-ID: <541C44AD.8080207@gmail.com>

Hi Mark,

As a workaround for now, you can try converting the pixel values back to
world coordinates. If these do not match the coordinates you put in
originally (as in the example you showed us) then you can ignore the point.

Cheers,
Tom

Maik Riechert wrote:
> Just to add some context of what I'm doing. I got the star constellation 
> data from Marshall Perrin the other day on this list. And now I'm trying 
> to draw these constellations onto an image using WCS data. That means, 
> for each constellation, I convert the RA,DEC points to pixel coordinates 
> using wcs_world2pix, then I check whether all points are outside the 
> image bounds (in that case I skip drawing it), if they are partly or all 
> inside, then I draw the constellation.
> 
> So yes, I think the best way would be to return NaN in these cases. 
> Otherwise I wouldn't know how to easily filter out those wrong points.
> 
> Cheers
> Maik
> 
> 
> On 19/09/14 15:14, Thomas Robitaille wrote:
>> Ah of course, this is indeed what is going on here! I agree that it's
>> worth thinking about whether cases like this should return an error.
>> In the past (in WCSAxes) I've simply checked if the coordinate
>> round-trips in order to determine if it's in the observational plane,
>> but it may be more sensible to simply return NaN.
>>
>> Cheers,
>> Tom
>>
>> On 19 September 2014 14:14, David Berry <d.berry at jach.hawaii.edu> wrote:
>>> Am I missing something? This is a TAN projection centred on CRVAL1,
>>> CRVAL2#. Since it is a TAN projection, the projection plane only
>>> includes half the sky - i.e. the hemisphere centred on (16,23). But
>>> the test point (211,-26) is not contained within this hemisphere and
>>> so is not included in the TAN projection plane. In other words, no
>>> pixel has the coordinates RA!1 Dec=-26, and so the results of  using
>>> wcs.wcs_world2pix should be NaN, or "invalid", or something.
>>>
>>> Unless I'm missing something...
>>>
>>> David
>>>
>>>
>>> On 19 September 2014 12:58, Bob Garwood <bgarwood at nrao.edu> wrote:
>>>> I suspect what's going on here has to do with the specific CD matrix, which
>>>> includes rotation. I think because of that rotation the world coordinate
>>>> actually maps back in to the grid at the antipode. I haven't checked this by
>>>> hand to see if that's the case.
>>>>
>>>> Bob
>>>>
>>>> On September 19, 2014 7:47:30 AM EDT, Howard Bushouse <bushouse at stsci.edu>
>>>> wrote:
>>>>> Huh. But that?s not how astronomers measure RA and Dec, even when
>>>>> translated to degrees. If I?ve got an object with an RA of 17:45:00.0
>>>>> (hh:mm:ss.w) the RA in degrees is 266.25. We *never* use a negative RA.
>>>>> Instead of a range of -180 to 180, we use 0 to 360. Dec is the only one that
>>>>> ever goes negative (-90 to +90, as you indicated).
>>>>>
>>>>> -hb
>>>>>
>>>>> On Sep 18, 2014, at 8:26 PM, Michael Droettboom <mdroe at stsci.edu> wrote:
>>>>>
>>>>>>   The range of ra and dec is (-180, 180) and (-90, 90) respectively.
>>>>>>   (211, -26) is equivalent to (31, 26).
>>>>>>
>>>>>>   Mike
>>>>>>
>>>>>>   On 09/18/2014 05:04 PM, Maik Riechert wrote:
>>>>>>>   Hi,
>>>>>>>
>>>>>>>   I'm having some great trouble currently and am a bit confused to!
>>>>>>>   o:
>>>>>>>
>>>>>>>
>>>>>>>   wcs =CS(header)
>>>>>>>   x,y =cs.wcs_world2pix(211, -26, 0)
>>>>>>>   print x,y # 836.316942718 658.26364248
>>>>>>>   ra,dec =cs.wcs_pix2world(x, y, 0)
>>>>>>>   print ra, dec # 31.0 26.0
>>>>>>>
>>>>>>>   It seems like world2pix gives me bogus results. I was expecting values
>>>>>>>   way outside my image area (image size is 4256x2832). Am I doing
>>>>>>>   something obvious wrong?
>>>>>>>
>>>>>>>   The WCS headers can be seen at http://pastebin.com/JrdiL949
>>>>>>>
>>>>>>>   Thanks for the help,
>>>>>>>   Maik
>>>>>>> ________________________________
>>>>>>>
>>>>>>>   AstroPy mailing list
>>>>>>>   AstroPy at scipy.org
>>>>>>>   http://mail.scipy.org/mailman/listinfo/astropy
>>>>>>
>>>>>>   --
>>>>>>   Michael Droettboom
>>>>>>   Science Software Branch
>>>>>>   Space Telescope Science Institute
>>>>>>
>>>>>>   http://www.droettboom.com
>>>>>>
>>>>>> ________________________________
>>>>>>
>>>>>>   AstroPy mailing list
>>>>>>   AstroPy at scipy.or!
>>>>>>   g
>>>>>>
>>>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>>> ________________________________
>>>>>
>>>>> AstroPy mailing list
>>>>> AstroPy at scipy.org
>>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>> _______________________________________________
>>>> AstroPy mailing list
>>>> AstroPy at scipy.org
>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>>
>>> _______________________________________________
>>> AstroPy mailing list
>>> AstroPy at scipy.org
>>> http://mail.scipy.org/mailman/listinfo/astropy
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy


From eglez at ast.cam.ac.uk  Fri Sep 19 11:22:36 2014
From: eglez at ast.cam.ac.uk (Eduardo Gonzalez-Solares)
Date: Fri, 19 Sep 2014 16:22:36 +0100
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <541C444A.3090900@arcor.de>
References: <541B48D1.5060902@arcor.de>
	<541B781E.1010203@stsci.edu>	<517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>	<b944306b-aeb5-4d57-9aec-23dc60d39e74@email.android.com>	<CAALafn6OB=foNWdnRYKAa-P9ZExe0DXWbby-gA4r1G_DJdasQA@mail.gmail.com>
	<CAGMHX_1AJ_Vr+omJpkkOGrQwrBOL29pbocrv4EuudYp+u=kHdw@mail.gmail.com>
	<541C444A.3090900@arcor.de>
Message-ID: <6E901D02-E244-43C2-9026-D6B5A1D8DD8F@ast.cam.ac.uk>

As others have said you cannot represent the whole sky using only one TAN projection. More than a bug it is a "feature". What I would do is check first that your constellation is at a roughly reasonable distance (depends on the size of your image) of the centre of your image. That would probably make your routine quicker too.

Cheers,

Eduardo

On 19 Sep 2014, at 15:57, Maik Riechert <maik.riechert at arcor.de> wrote:

> Just to add some context of what I'm doing. I got the star constellation 
> data from Marshall Perrin the other day on this list. And now I'm trying 
> to draw these constellations onto an image using WCS data. That means, 
> for each constellation, I convert the RA,DEC points to pixel coordinates 
> using wcs_world2pix, then I check whether all points are outside the 
> image bounds (in that case I skip drawing it), if they are partly or all 
> inside, then I draw the constellation.
> 
> So yes, I think the best way would be to return NaN in these cases. 
> Otherwise I wouldn't know how to easily filter out those wrong points.
> 
> Cheers
> Maik
> 
> 
> On 19/09/14 15:14, Thomas Robitaille wrote:
>> Ah of course, this is indeed what is going on here! I agree that it's
>> worth thinking about whether cases like this should return an error.
>> In the past (in WCSAxes) I've simply checked if the coordinate
>> round-trips in order to determine if it's in the observational plane,
>> but it may be more sensible to simply return NaN.
>> 
>> Cheers,
>> Tom
>> 
>> On 19 September 2014 14:14, David Berry <d.berry at jach.hawaii.edu> wrote:
>>> Am I missing something? This is a TAN projection centred on CRVAL1,
>>> CRVAL2#. Since it is a TAN projection, the projection plane only
>>> includes half the sky - i.e. the hemisphere centred on (16,23). But
>>> the test point (211,-26) is not contained within this hemisphere and
>>> so is not included in the TAN projection plane. In other words, no
>>> pixel has the coordinates RA!1 Dec=-26, and so the results of  using
>>> wcs.wcs_world2pix should be NaN, or "invalid", or something.
>>> 
>>> Unless I'm missing something...
>>> 
>>> David
>>> 
>>> 
>>> On 19 September 2014 12:58, Bob Garwood <bgarwood at nrao.edu> wrote:
>>>> I suspect what's going on here has to do with the specific CD matrix, which
>>>> includes rotation. I think because of that rotation the world coordinate
>>>> actually maps back in to the grid at the antipode. I haven't checked this by
>>>> hand to see if that's the case.
>>>> 
>>>> Bob
>>>> 
>>>> On September 19, 2014 7:47:30 AM EDT, Howard Bushouse <bushouse at stsci.edu>
>>>> wrote:
>>>>> Huh. But that?s not how astronomers measure RA and Dec, even when
>>>>> translated to degrees. If I?ve got an object with an RA of 17:45:00.0
>>>>> (hh:mm:ss.w) the RA in degrees is 266.25. We *never* use a negative RA.
>>>>> Instead of a range of -180 to 180, we use 0 to 360. Dec is the only one that
>>>>> ever goes negative (-90 to +90, as you indicated).
>>>>> 
>>>>> -hb
>>>>> 
>>>>> On Sep 18, 2014, at 8:26 PM, Michael Droettboom <mdroe at stsci.edu> wrote:
>>>>> 
>>>>>>  The range of ra and dec is (-180, 180) and (-90, 90) respectively.
>>>>>>  (211, -26) is equivalent to (31, 26).
>>>>>> 
>>>>>>  Mike
>>>>>> 
>>>>>>  On 09/18/2014 05:04 PM, Maik Riechert wrote:
>>>>>>>  Hi,
>>>>>>> 
>>>>>>>  I'm having some great trouble currently and am a bit confused to!
>>>>>>>  o:
>>>>>>> 
>>>>>>> 
>>>>>>>  wcs =CS(header)
>>>>>>>  x,y =cs.wcs_world2pix(211, -26, 0)
>>>>>>>  print x,y # 836.316942718 658.26364248
>>>>>>>  ra,dec =cs.wcs_pix2world(x, y, 0)
>>>>>>>  print ra, dec # 31.0 26.0
>>>>>>> 
>>>>>>>  It seems like world2pix gives me bogus results. I was expecting values
>>>>>>>  way outside my image area (image size is 4256x2832). Am I doing
>>>>>>>  something obvious wrong?
>>>>>>> 
>>>>>>>  The WCS headers can be seen at http://pastebin.com/JrdiL949
>>>>>>> 
>>>>>>>  Thanks for the help,
>>>>>>>  Maik
>>>>>>> ________________________________
>>>>>>> 
>>>>>>>  AstroPy mailing list
>>>>>>>  AstroPy at scipy.org
>>>>>>>  http://mail.scipy.org/mailman/listinfo/astropy
>>>>>> 
>>>>>> 
>>>>>>  --
>>>>>>  Michael Droettboom
>>>>>>  Science Software Branch
>>>>>>  Space Telescope Science Institute
>>>>>> 
>>>>>>  http://www.droettboom.com
>>>>>> 
>>>>>> ________________________________
>>>>>> 
>>>>>>  AstroPy mailing list
>>>>>>  AstroPy at scipy.or!
>>>>>>  g
>>>>>> 
>>>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>>> 
>>>>> ________________________________
>>>>> 
>>>>> AstroPy mailing list
>>>>> AstroPy at scipy.org
>>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>> 
>>>> _______________________________________________
>>>> AstroPy mailing list
>>>> AstroPy at scipy.org
>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>> 
>>> _______________________________________________
>>> AstroPy mailing list
>>> AstroPy at scipy.org
>>> http://mail.scipy.org/mailman/listinfo/astropy
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy



From maik.riechert at arcor.de  Sat Sep 20 07:23:53 2014
From: maik.riechert at arcor.de (Maik Riechert)
Date: Sat, 20 Sep 2014 13:23:53 +0200
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <6E901D02-E244-43C2-9026-D6B5A1D8DD8F@ast.cam.ac.uk>
References: <541B48D1.5060902@arcor.de>	<541B781E.1010203@stsci.edu>	<517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>	<b944306b-aeb5-4d57-9aec-23dc60d39e74@email.android.com>	<CAALafn6OB=foNWdnRYKAa-P9ZExe0DXWbby-gA4r1G_DJdasQA@mail.gmail.com>	<CAGMHX_1AJ_Vr+omJpkkOGrQwrBOL29pbocrv4EuudYp+u=kHdw@mail.gmail.com>	<541C444A.3090900@arcor.de>
	<6E901D02-E244-43C2-9026-D6B5A1D8DD8F@ast.cam.ac.uk>
Message-ID: <541D63C9.5090306@arcor.de>

I still think it's a bug, but anyway, I worked around it be converting
to RA,Dec again. This is way easier than somehow calculating the
distance for arbitrary WCS.

The code is here for interested people:
https://gist.github.com/neothemachine/2fd64d7a552ba7743ce7

It's not directly usable (e.g. misses constellation data) but the code
should give useful insights.

An example image:
http://oi62.tinypic.com/sncjkp.jpg

(Note that I used padding of 10px around stars and clipped the drawing
below the horizon.)

Cheers and thanks!
Maik

Am 19.09.2014 17:22, schrieb Eduardo Gonzalez-Solares:
> As others have said you cannot represent the whole sky using only one TAN projection. More than a bug it is a "feature". What I would do is check first that your constellation is at a roughly reasonable distance (depends on the size of your image) of the centre of your image. That would probably make your routine quicker too.
> 
> Cheers,
> 
> Eduardo
> 
> On 19 Sep 2014, at 15:57, Maik Riechert <maik.riechert at arcor.de> wrote:
> 
>> Just to add some context of what I'm doing. I got the star constellation 
>> data from Marshall Perrin the other day on this list. And now I'm trying 
>> to draw these constellations onto an image using WCS data. That means, 
>> for each constellation, I convert the RA,DEC points to pixel coordinates 
>> using wcs_world2pix, then I check whether all points are outside the 
>> image bounds (in that case I skip drawing it), if they are partly or all 
>> inside, then I draw the constellation.
>>
>> So yes, I think the best way would be to return NaN in these cases. 
>> Otherwise I wouldn't know how to easily filter out those wrong points.
>>
>> Cheers
>> Maik
>>
>>
>> On 19/09/14 15:14, Thomas Robitaille wrote:
>>> Ah of course, this is indeed what is going on here! I agree that it's
>>> worth thinking about whether cases like this should return an error.
>>> In the past (in WCSAxes) I've simply checked if the coordinate
>>> round-trips in order to determine if it's in the observational plane,
>>> but it may be more sensible to simply return NaN.
>>>
>>> Cheers,
>>> Tom
>>>
>>> On 19 September 2014 14:14, David Berry <d.berry at jach.hawaii.edu> wrote:
>>>> Am I missing something? This is a TAN projection centred on CRVAL1,
>>>> CRVAL2#. Since it is a TAN projection, the projection plane only
>>>> includes half the sky - i.e. the hemisphere centred on (16,23). But
>>>> the test point (211,-26) is not contained within this hemisphere and
>>>> so is not included in the TAN projection plane. In other words, no
>>>> pixel has the coordinates RA!1 Dec=6, and so the results of  using
>>>> wcs.wcs_world2pix should be NaN, or "invalid", or something.
>>>>
>>>> Unless I'm missing something...
>>>>
>>>> David
>>>>
>>>>
>>>> On 19 September 2014 12:58, Bob Garwood <bgarwood at nrao.edu> wrote:
>>>>> I suspect what's going on here has to do with the specific CD matrix, which
>>>>> includes rotation. I think because of that rotation the world coordinate
>>>>> actually maps back in to the grid at the antipode. I haven't checked this by
>>>>> hand to see if that's the case.
>>>>>
>>>>> Bob
>>>>>
>>>>> On September 19, 2014 7:47:30 AM EDT, Howard Bushouse <bushouse at stsci.edu>
>>>>> wrote:
>>>>>> Huh. But that?s not how astronomers measure RA and Dec, even when
>>>>>> translated to degrees. If I?ve got an object with an RA of 17:45:00.0
>>>>>> (hh:mm:ss.w) the RA in degrees is 266.25. We *never* use a negative RA.
>>>>>> Instead of a range of -180 to 180, we use 0 to 360. Dec is the only one that
>>>>>> ever goes negative (-90 to +90, as you indicated).
>>>>>>
>>>>>> -hb
>>>>>>
>>>>>> On Sep 18, 2014, at 8:26 PM, Michael Droettboom <mdroe at stsci.edu> wrote:
>>>>>>
>>>>>>>  The range of ra and dec is (-180, 180) and (-90, 90) respectively.
>>>>>>>  (211, -26) is equivalent to (31, 26).
>>>>>>>
>>>>>>>  Mike
>>>>>>>
>>>>>>>  On 09/18/2014 05:04 PM, Maik Riechert wrote:
>>>>>>>>  Hi,
>>>>>>>>
>>>>>>>>  I'm having some great trouble currently and am a bit confused to!
>>>>>>>>  o:
>>>>>>>>
>>>>>>>>
>>>>>>>>  wcs =(header)
>>>>>>>>  x,y =.wcs_world2pix(211, -26, 0)
>>>>>>>>  print x,y # 836.316942718 658.26364248
>>>>>>>>  ra,dec =.wcs_pix2world(x, y, 0)
>>>>>>>>  print ra, dec # 31.0 26.0
>>>>>>>>
>>>>>>>>  It seems like world2pix gives me bogus results. I was expecting values
>>>>>>>>  way outside my image area (image size is 4256x2832). Am I doing
>>>>>>>>  something obvious wrong?
>>>>>>>>
>>>>>>>>  The WCS headers can be seen at http://pastebin.com/JrdiL949
>>>>>>>>
>>>>>>>>  Thanks for the help,
>>>>>>>>  Maik
>>>>>>>> ________________________________
>>>>>>>>
>>>>>>>>  AstroPy mailing list
>>>>>>>>  AstroPy at scipy.org
>>>>>>>>  http://mail.scipy.org/mailman/listinfo/astropy
>>>>>>>
>>>>>>>
>>>>>>>  --
>>>>>>>  Michael Droettboom
>>>>>>>  Science Software Branch
>>>>>>>  Space Telescope Science Institute
>>>>>>>
>>>>>>>  http://www.droettboom.com
>>>>>>>
>>>>>>> ________________________________
>>>>>>>
>>>>>>>  AstroPy mailing list
>>>>>>>  AstroPy at scipy.or!
>>>>>>>  g
>>>>>>>
>>>>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>>>>
>>>>>> ________________________________
>>>>>>
>>>>>> AstroPy mailing list
>>>>>> AstroPy at scipy.org
>>>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>>>
>>>>> _______________________________________________
>>>>> AstroPy mailing list
>>>>> AstroPy at scipy.org
>>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>>>
>>>> _______________________________________________
>>>> AstroPy mailing list
>>>> AstroPy at scipy.org
>>>> http://mail.scipy.org/mailman/listinfo/astropy
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
> 
> 



From mdroe at stsci.edu  Sat Sep 20 17:58:42 2014
From: mdroe at stsci.edu (Michael Droettboom)
Date: Sat, 20 Sep 2014 17:58:42 -0400
Subject: [AstroPy] Bug in wcs_world2pix?
In-Reply-To: <541D63C9.5090306@arcor.de>
References: <541B48D1.5060902@arcor.de>	<541B781E.1010203@stsci.edu>	<517EE012-277C-477C-B30C-7784EBB60186@stsci.edu>	<b944306b-aeb5-4d57-9aec-23dc60d39e74@email.android.com>	<CAALafn6OB=foNWdnRYKAa-P9ZExe0DXWbby-gA4r1G_DJdasQA@mail.gmail.com>	<CAGMHX_1AJ_Vr+omJpkkOGrQwrBOL29pbocrv4EuudYp+u=kHdw@mail.gmail.com>	<541C444A.3090900@arcor.de>	<6E901D02-E244-43C2-9026-D6B5A1D8DD8F@ast.cam.ac.uk>
	<541D63C9.5090306@arcor.de>
Message-ID: <541DF892.9030008@stsci.edu>

With the help of Mark Calabretta convincing me those input RA and Dec 
should be rejected by bounds checking and marked as invalid, I 
discovered a long standing and strangely-never-noticed bug in astropy.  
It was checking for the wrong status code that indicates when one of the 
input world coordinates is invalid -- the status codes are different for 
wcsp2s and wcss2p, and I think I just didn't notice that.

A fix is available in the linked PR below, which should make it into the 
next bugfix release of astropy.  With this fix, your example will now 
return the pixel coordinates as "nan", which is how astropy.wcs 
indicates invalid values.

https://github.com/astropy/astropy/pull/2965

Mike

On 09/20/2014 07:23 AM, Maik Riechert wrote:
> I still think it's a bug, but anyway, I worked around it be converting
> to RA,Dec again. This is way easier than somehow calculating the
> distance for arbitrary WCS.
>
> The code is here for interested people:
> https://gist.github.com/neothemachine/2fd64d7a552ba7743ce7
>
> It's not directly usable (e.g. misses constellation data) but the code
> should give useful insights.
>
> An example image:
> http://oi62.tinypic.com/sncjkp.jpg
>
> (Note that I used padding of 10px around stars and clipped the drawing
> below the horizon.)
>
> Cheers and thanks!
> Maik
>
> Am 19.09.2014 17:22, schrieb Eduardo Gonzalez-Solares:
>> As others have said you cannot represent the whole sky using only one TAN projection. More than a bug it is a "feature". What I would do is check first that your constellation is at a roughly reasonable distance (depends on the size of your image) of the centre of your image. That would probably make your routine quicker too.
>>
>> Cheers,
>>
>> Eduardo
>>
>> On 19 Sep 2014, at 15:57, Maik Riechert <maik.riechert at arcor.de> wrote:
>>
>>> Just to add some context of what I'm doing. I got the star constellation
>>> data from Marshall Perrin the other day on this list. And now I'm trying
>>> to draw these constellations onto an image using WCS data. That means,
>>> for each constellation, I convert the RA,DEC points to pixel coordinates
>>> using wcs_world2pix, then I check whether all points are outside the
>>> image bounds (in that case I skip drawing it), if they are partly or all
>>> inside, then I draw the constellation.
>>>
>>> So yes, I think the best way would be to return NaN in these cases.
>>> Otherwise I wouldn't know how to easily filter out those wrong points.
>>>
>>> Cheers
>>> Maik
>>>
>>>
>>> On 19/09/14 15:14, Thomas Robitaille wrote:
>>>> Ah of course, this is indeed what is going on here! I agree that it's
>>>> worth thinking about whether cases like this should return an error.
>>>> In the past (in WCSAxes) I've simply checked if the coordinate
>>>> round-trips in order to determine if it's in the observational plane,
>>>> but it may be more sensible to simply return NaN.
>>>>
>>>> Cheers,
>>>> Tom
>>>>
>>>> On 19 September 2014 14:14, David Berry <d.berry at jach.hawaii.edu> wrote:
>>>>> Am I missing something? This is a TAN projection centred on CRVAL1,
>>>>> CRVAL2#. Since it is a TAN projection, the projection plane only
>>>>> includes half the sky - i.e. the hemisphere centred on (16,23). But
>>>>> the test point (211,-26) is not contained within this hemisphere and
>>>>> so is not included in the TAN projection plane. In other words, no
>>>>> pixel has the coordinates RA!1 Dec=6, and so the results of  using
>>>>> wcs.wcs_world2pix should be NaN, or "invalid", or something.
>>>>>
>>>>> Unless I'm missing something...
>>>>>
>>>>> David
>>>>>
>>>>>
>>>>> On 19 September 2014 12:58, Bob Garwood <bgarwood at nrao.edu> wrote:
>>>>>> I suspect what's going on here has to do with the specific CD matrix, which
>>>>>> includes rotation. I think because of that rotation the world coordinate
>>>>>> actually maps back in to the grid at the antipode. I haven't checked this by
>>>>>> hand to see if that's the case.
>>>>>>
>>>>>> Bob
>>>>>>
>>>>>> On September 19, 2014 7:47:30 AM EDT, Howard Bushouse <bushouse at stsci.edu>
>>>>>> wrote:
>>>>>>> Huh. But that?s not how astronomers measure RA and Dec, even when
>>>>>>> translated to degrees. If I?ve got an object with an RA of 17:45:00.0
>>>>>>> (hh:mm:ss.w) the RA in degrees is 266.25. We *never* use a negative RA.
>>>>>>> Instead of a range of -180 to 180, we use 0 to 360. Dec is the only one that
>>>>>>> ever goes negative (-90 to +90, as you indicated).
>>>>>>>
>>>>>>> -hb
>>>>>>>
>>>>>>> On Sep 18, 2014, at 8:26 PM, Michael Droettboom <mdroe at stsci.edu> wrote:
>>>>>>>
>>>>>>>>   The range of ra and dec is (-180, 180) and (-90, 90) respectively.
>>>>>>>>   (211, -26) is equivalent to (31, 26).
>>>>>>>>
>>>>>>>>   Mike
>>>>>>>>
>>>>>>>>   On 09/18/2014 05:04 PM, Maik Riechert wrote:
>>>>>>>>>   Hi,
>>>>>>>>>
>>>>>>>>>   I'm having some great trouble currently and am a bit confused to!
>>>>>>>>>   o:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>   wcs =(header)
>>>>>>>>>   x,y =.wcs_world2pix(211, -26, 0)
>>>>>>>>>   print x,y # 836.316942718 658.26364248
>>>>>>>>>   ra,dec =.wcs_pix2world(x, y, 0)
>>>>>>>>>   print ra, dec # 31.0 26.0
>>>>>>>>>
>>>>>>>>>   It seems like world2pix gives me bogus results. I was expecting values
>>>>>>>>>   way outside my image area (image size is 4256x2832). Am I doing
>>>>>>>>>   something obvious wrong?
>>>>>>>>>
>>>>>>>>>   The WCS headers can be seen at http://pastebin.com/JrdiL949
>>>>>>>>>
>>>>>>>>>   Thanks for the help,
>>>>>>>>>   Maik
>>>>>>>>> ________________________________
>>>>>>>>>
>>>>>>>>>   AstroPy mailing list
>>>>>>>>>   AstroPy at scipy.org
>>>>>>>>>   http://mail.scipy.org/mailman/listinfo/astropy
>>>>>>>>
>>>>>>>>   --
>>>>>>>>   Michael Droettboom
>>>>>>>>   Science Software Branch
>>>>>>>>   Space Telescope Science Institute
>>>>>>>>
>>>>>>>>   http://www.droettboom.com
>>>>>>>>
>>>>>>>> ________________________________
>>>>>>>>
>>>>>>>>   AstroPy mailing list
>>>>>>>>   AstroPy at scipy.or!
>>>>>>>>   g
>>>>>>>>
>>>>>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>>>>> ________________________________
>>>>>>>
>>>>>>> AstroPy mailing list
>>>>>>> AstroPy at scipy.org
>>>>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>>>> _______________________________________________
>>>>>> AstroPy mailing list
>>>>>> AstroPy at scipy.org
>>>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>>>>
>>>>> _______________________________________________
>>>>> AstroPy mailing list
>>>>> AstroPy at scipy.org
>>>>> http://mail.scipy.org/mailman/listinfo/astropy
>>> _______________________________________________
>>> AstroPy mailing list
>>> AstroPy at scipy.org
>>> http://mail.scipy.org/mailman/listinfo/astropy
>>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy


-- 
Michael Droettboom
Science Software Branch
Space Telescope Science Institute

http://www.droettboom.com



From wkerzendorf at gmail.com  Sun Sep 21 09:35:40 2014
From: wkerzendorf at gmail.com (Wolfgang Kerzendorf)
Date: Sun, 21 Sep 2014 09:35:40 -0400
Subject: [AstroPy] question re specutils
In-Reply-To: <541B3D75.6000209@gmail.com>
References: <CAE6Lf2_KaJkeg+WX7_ooe_gy4z3qdS_YPqmX3P0k9HhzZPnAvg@mail.gmail.com>
	<5419A45D.6060401@stsci.edu>
	<CAE6Lf28Qn0jinqdJYLzOF+q6NtFBQwxmHXJ5KxcZXM-Cud895Q@mail.gmail.com>
	<5419A628.3020108@stsci.edu>
	<CAE6Lf28DVhMWvR7KhSVATg=f-ULNvztaJnYeGRPFLPR30e1PBw@mail.gmail.com>
	<5419F1A8.8060604@stsci.edu>
	<CAE6Lf2_5rC1A2BJWbt7ACy_=4Nifd_m+CidS=zML4t0=mFX1=g@mail.gmail.com>
	<541B18BD.6010004@gmail.com>
	<CAH33GGE+tdums-43ja_Zsdeqj84TiFz0EMxfWW13mmNO45aw=g@mail.gmail.com>
	<541B3D75.6000209@gmail.com>
Message-ID: <CAH33GGHfYQJttYH+Z8DNT74V8-EhbRcJoDn5KFRX1AHagf+nhg@mail.gmail.com>

Hi Tom,

Yes there are plans for a 0.1 release, but there are still some specwcs
features that should be easily implementable that I want to stick in there
before releasing. But it is on my agenda.

Cheers,
   Wolfgang

On Thu, Sep 18, 2014 at 4:15 PM, Thomas Robitaille <
thomas.robitaille at gmail.com> wrote:

> Hi Wolfgang,
>
> Thanks for clarifying this! Are there plans for a 0.1 release, since
> this would make it easier for people to try it out?
>
> Cheers,
> Tom
>
> Wolfgang Kerzendorf wrote:
> > Hi Aycha,
> >
> > Erik B. has already given a relatively good instruction how to install
> > specutils. As Tom R. said there has not been an official release of
> > specutils, however it is ready for science (and is also being used for
> > that ;-) ). Obviously it depends on what the science you want to do.
> > Kyle et al. has written the extinction part and documentation and it is
> > mostly ready for consumption (I used it a couple of times).
> >
> > It is pretty clearly laid out in the document that Erik sent
> > (
> http://docs.astropy.org/en/stable/install.html#obtaining-the-source-packages
> )
> >  of what to do -- including the need to install cython.
> >
> > Let us know how it goes,
> >     Wolfgang
> >
> > On Thu, Sep 18, 2014 at 1:39 PM, Thomas Robitaille
> > <thomas.robitaille at gmail.com <mailto:thomas.robitaille at gmail.com>>
> wrote:
> >
> >     Hi Aycha,
> >
> >     Just to echo what Erik Bray said, there hasn't actually been a
> specutils
> >     release yet, so in addition to meaning that it is a bit harder to
> >     install, the package may not be ready for 'science' use yet (and the
> API
> >     may not be stable).
> >
> >     Maybe Wolfgang or someone else involved in specutils can give an
> update
> >     on the current status?
> >
> >     Cheers,
> >     Tom
> >
> >     Aycha Tammour wrote:
> >     > Erik,
> >     >
> >     > pip install specutils was not able to install the package (No
> >     > distributions at all found for specutils) even when I tried
> >     > --allow-unvirified and --allow-external.
> >     >
> >     > Although pip search specutils seemed to find the package.
> >     >
> >     > I tried installing from source on a MAC and a unix machine and got
> >     error
> >     > messages about cythoning some file (code.py, I think).
> >     >
> >     > Best,
> >     > Aycha
> >     >
> >     > On Wed, Sep 17, 2014 at 4:40 PM, Erik Bray <embray at stsci.edu
> >     <mailto:embray at stsci.edu>
> >     > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>> wrote:
> >     >
> >     >     On 09/17/2014 11:46 AM, Aycha Tammour wrote:
> >     >     > Thanks Erik. This makes sense but there is actually a
> >     >     setup_package.py file in
> >     >     > the directory which I used to install specutils with
> >     >     >
> >     >     > python setup_package.py install
> >     >     >
> >     >     > Nothing showed on my terminal which seems a bit suspicious.
> >     >
> >     >     setup_package.py is not the file you are looking for.
> >     >
> >     >     Please follow the instructions at
> >     >
> >     >
> >
> http://docs.astropy.org/en/stable/install.html#obtaining-the-source-packages
> >     >
> >     >     if you want to install from source, or better still just do
> `pip
> >     >     install specutils`.
> >     >
> >     >     Erik
> >     >
> >     >     > On Wed, Sep 17, 2014 at 11:18 AM, Erik Bray <
> embray at stsci.edu
> >     <mailto:embray at stsci.edu>
> >     >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>
> >     >     > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>
> >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>>> wrote:
> >     >     >
> >     >     >     On 09/17/2014 11:15 AM, Aycha Tammour wrote:
> >     >     >     > Hi Erik,
> >     >     >     >
> >     >     >     > specutils.__version__
> >     >     >     > ''
> >     >     >     >
> >     >     >     > specutils.__file__
> >     >     >     > 'specutils/__init__.py'
> >     >     >     >
> >     >     >     > The package I am using is the one I grabbed from the
> >     github
> >     >     repo just yesterday.
> >     >     >
> >     >     >     It sounds like you're just trying to import the package
> >     >     directly out of the
> >     >     >     repository clone without building the package first or
> >     >     installing it.
> >     >     >
> >     >     >     It looks like specutils doesn't have installation
> >     instructions
> >     >     as such, but I
> >     >     >     recommend looking at the installation instructions for
> >     Astropy
> >     >     as it applies all
> >     >     >     the same:
> >     >     >
> >     >     >     http://docs.astropy.org/en/stable/install.html
> >     >     >
> >     >     >     Erik
> >     >     >
> >     >     >     > On Wed, Sep 17, 2014 at 11:10 AM, Erik Bray
> >     <embray at stsci.edu <mailto:embray at stsci.edu>
> >     >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>
> >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>
> >     >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>>
> >     >     >      > <mailto:embray at stsci.edu <mailto:embray at stsci.edu>
> >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>
> >     >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>
> >     <mailto:embray at stsci.edu <mailto:embray at stsci.edu>>>>> wrote:
> >     >     >      >
> >     >     >      >     On 09/17/2014 10:12 AM, Aycha Tammour wrote:
> >     >     >      >     > Hi,
> >     >     >      >     >
> >     >     >      >     > I have a question about one of Astropy's
> affiliated
> >     >     packages and I
> >     >     >     hope someone
> >     >     >      >     > here can help with it.
> >     >     >      >     > I am trying to use specutils' extinction module
> but
> >     >     it seems I am
> >     >     >     unable to
> >     >     >      >     > import it.
> >     >     >      >     >
> >     >     >      >     > I tried:
> >     >     >      >     > import specutils
> >     >     >      >     > specutils.extinction.extinction_ccm89(wave,
> >     r_v=3.1)
> >     >     >      >     > And got:
> >     >     >      >     > AttributeError: 'module' object has no attribute
> >     >     'extinction'
> >     >     >      >     >
> >     >     >      >     > When I tried:
> >     >     >      >     > from specutils import extinction
> >     >     >      >     > I still got
> >     >     >      >     > ImportError: cannot import name extinction
> >     >     >      >     >
> >     >     >      >     > Am I missing something here? I should mention
> >     that I
> >     >     was able to
> >     >     >     use some of the
> >     >     >      >     > functionality in spectrum1D.
> >     >     >      >
> >     >     >      >     When you import specutils what do
> >     >     >      >
> >     >     >      >       >>> specutils.__version__
> >     >     >      >
> >     >     >      >     and
> >     >     >      >
> >     >     >      >       >>> specutils.__file__
> >     >     >      >
> >     >     >      >     show?
> >     >     >      >
> >     >     >      >     _______________________________________________
> >     >     >      >     AstroPy mailing list
> >     >     >      > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
> >     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>>
> >     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
> >     >     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>>>
> >     >     >      > http://mail.scipy.org/mailman/listinfo/astropy
> >     >     >      >
> >     >     >      >
> >     >     >      >
> >     >     >      >
> >     >     >      >
> >     >     >      >
> >     >     >      > _______________________________________________
> >     >     >      > AstroPy mailing list
> >     >     >      > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
> >     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>>
> >     >     >      > http://mail.scipy.org/mailman/listinfo/astropy
> >     >     >      >
> >     >     >
> >     >     >     _______________________________________________
> >     >     >     AstroPy mailing list
> >     >     >     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
> >     >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>>
> >     >     >     http://mail.scipy.org/mailman/listinfo/astropy
> >     >     >
> >     >     >
> >     >     >
> >     >     >
> >     >     >
> >     >     >
> >     >     > _______________________________________________
> >     >     > AstroPy mailing list
> >     >     > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
> >     >     > http://mail.scipy.org/mailman/listinfo/astropy
> >     >     >
> >     >
> >     >     _______________________________________________
> >     >     AstroPy mailing list
> >     >     AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     <mailto:AstroPy at scipy.org <mailto:AstroPy at scipy.org>>
> >     >     http://mail.scipy.org/mailman/listinfo/astropy
> >     >
> >     >
> >     >
> >     >
> >     > --
> >     > Aycha Tammour
> >     > Astronomy PhD Candidate
> >     > University of Western Ontario
> >     >
> >     > _______________________________________________
> >     > AstroPy mailing list
> >     > AstroPy at scipy.org <mailto:AstroPy at scipy.org>
> >     > http://mail.scipy.org/mailman/listinfo/astropy
> >
> >
> > _______________________________________________
> > AstroPy mailing list
> > AstroPy at scipy.org
> > http://mail.scipy.org/mailman/listinfo/astropy
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>
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From kaustubh.waghmare at gmail.com  Wed Sep 24 06:19:02 2014
From: kaustubh.waghmare at gmail.com (Kaustubh Waghmare)
Date: Wed, 24 Sep 2014 15:49:02 +0530
Subject: [AstroPy] HTM ID Tools in Python
Message-ID: <CA+YVjRCnAgW0J-oPRrXznRKa7_z_s1ucjg__9Fpt2+x3iko68w@mail.gmail.com>

Hi All,

I came across this package called esutils which can be found at :
https://code.google.com/p/esutil/

A key limitation of this tool:
* Does not allow for HTM depth of more than 13 owing to the 32 bit integer
type used in the underlying C program.

I have done a lot of searching but came across the tools / APIs available
www.skyserver.org but they are largely based on C#, C++ and Java.

Can someone
a) point to any utilities similar to the esutils' HTM sub-module but
without the depth 13 problem OR
b) any hack I could do to the esutils source code to make it work beyond
depth 13?

Thanks in advance.

Cheers,
Kaustubh
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From erin.sheldon at gmail.com  Wed Sep 24 08:16:43 2014
From: erin.sheldon at gmail.com (Erin Sheldon)
Date: Wed, 24 Sep 2014 08:16:43 -0400
Subject: [AstroPy] HTM ID Tools in Python
In-Reply-To: <CA+YVjRCnAgW0J-oPRrXznRKa7_z_s1ucjg__9Fpt2+x3iko68w@mail.gmail.com>
References: <CA+YVjRCnAgW0J-oPRrXznRKa7_z_s1ucjg__9Fpt2+x3iko68w@mail.gmail.com>
Message-ID: <CABOnLw0Csc93ZaXS79nGTu+9boqeCwpkzcoXcmEXbwQYsugerA@mail.gmail.com>

Hi Kaustubh -

I'm the author of esutil.  Can you open an issue on esutil for this?
It should be simple to allow 64-bit.

-Erin Sheldon

On 9/24/14, Kaustubh Waghmare <kaustubh.waghmare at gmail.com> wrote:
> Hi All,
>
> I came across this package called esutils which can be found at :
> https://code.google.com/p/esutil/
>
> A key limitation of this tool:
> * Does not allow for HTM depth of more than 13 owing to the 32 bit integer
> type used in the underlying C program.
>
> I have done a lot of searching but came across the tools / APIs available
> www.skyserver.org but they are largely based on C#, C++ and Java.
>
> Can someone
> a) point to any utilities similar to the esutils' HTM sub-module but
> without the depth 13 problem OR
> b) any hack I could do to the esutils source code to make it work beyond
> depth 13?
>
> Thanks in advance.
>
> Cheers,
> Kaustubh
>


-- 
Erin Scott Sheldon
Brookhaven National Laboratory erin dot sheldon at gmail dot com


From kaustubh.waghmare at gmail.com  Wed Sep 24 14:08:34 2014
From: kaustubh.waghmare at gmail.com (Kaustubh Waghmare)
Date: Wed, 24 Sep 2014 23:38:34 +0530
Subject: [AstroPy] HTM ID Tools in Python
Message-ID: <CA+YVjRBOP2cWWMTSTAa+btv5ibtreBZKnjvj2dHQE+ZZshNWhQ@mail.gmail.com>

Hi Erin,

Thank you so much for the prompt reply. I have raised an issue as suggested
by you.

While I am at it, let me be a little more greedy ;) and ask mote questions
-

* Am I right in understanding that there is not straightforward class
method which can accept an RA, DEC and radius and output all HTM ID ranges
which will enable doing a cone search on a database for which HTM IDs have
been populated?

* If yes, can you point to any literature / resource which will help me
come up with such a code? So, in other words I am trying to code something
of the form "ConeSearch_withHTMid(ra, dec, radius)"? I believe this is
already being achieved by the API at www.skyserver.org but unfortunately,
as I understand, this works only for SQL Server 2005. This is explained at
the following page:
http://www.skyserver.org/HTM/HtmAPI/html/index.html

Thanks once again for all the help.

Cheers,
Kaustubh
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From erin.sheldon at gmail.com  Wed Sep 24 14:18:56 2014
From: erin.sheldon at gmail.com (Erin Sheldon)
Date: Wed, 24 Sep 2014 14:18:56 -0400
Subject: [AstroPy] HTM ID Tools in Python
In-Reply-To: <CA+YVjRBOP2cWWMTSTAa+btv5ibtreBZKnjvj2dHQE+ZZshNWhQ@mail.gmail.com>
References: <CA+YVjRBOP2cWWMTSTAa+btv5ibtreBZKnjvj2dHQE+ZZshNWhQ@mail.gmail.com>
Message-ID: <CABOnLw2x=VUguekXuztKFOTAgYLh1YOcX8K-74-L_mxGzMQ=tA@mail.gmail.com>

On 9/24/14, Kaustubh Waghmare <kaustubh.waghmare at gmail.com> wrote:
> Hi Erin,
>
> Thank you so much for the prompt reply. I have raised an issue as suggested
> by you.
>
> While I am at it, let me be a little more greedy ;) and ask mote questions
> -
>
> * Am I right in understanding that there is not straightforward class
> method which can accept an RA, DEC and radius and output all HTM ID ranges
> which will enable doing a cone search on a database for which HTM IDs have
> been populated?

Kaustubh -

the match() code uses that internally (it is called "intersecting");
it would be straightforward to expose this to python.  Please raise
another issue for that :)


> * If yes, can you point to any literature / resource which will help me
> come up with such a code? So, in other words I am trying to code something
> of the form "ConeSearch_withHTMid(ra, dec, radius)"? I believe this is
> already being achieved by the API at www.skyserver.org but unfortunately,
> as I understand, this works only for SQL Server 2005. This is explained at
> the following page:
> http://www.skyserver.org/HTM/HtmAPI/html/index.html
>
> Thanks once again for all the help.
>
> Cheers,
> Kaustubh
>


-- 
Erin Scott Sheldon
Brookhaven National Laboratory erin dot sheldon at gmail dot com


From erik.tollerud at gmail.com  Wed Sep 24 20:21:49 2014
From: erik.tollerud at gmail.com (Erik Tollerud)
Date: Wed, 24 Sep 2014 20:21:49 -0400
Subject: [AstroPy] Some Feedbacks about Astropy
In-Reply-To: <10502733.118251405135720835.JavaMail.coremail@mailweb>
References: <863181.3954441404220356854.JavaMail.coremail@mailweb>
	<CAARXUwUN2D7S0S8gihz6zqKhwXw7svGcZUpFLW_ThBrJyysgSw@mail.gmail.com>
	<10502733.118251405135720835.JavaMail.coremail@mailweb>
Message-ID: <CAARXUwU7184KLrP04OEEFCPAPT2fsQVgCwNMhA0kuhxR0bBYXA@mail.gmail.com>

FYI, there's a PR that expands on the matching feature currently under
review at

https://github.com/astropy/astropy/pull/2953

This adds a feature to search around a coordinate for all of the objects
nearby instead of just single matches.

That's still not the one-to-one matching, but it adds some features that
are of relevance there.  Specifically, returning matches where *both*
catalogs may not be completely represented in the sample (necessary for
one-to-one matching, but *not* in the current matching scheme).


Also, BTW, if anyone is looking at this and wants to know how to do
one-to-one, I think the simplest solution is to do the snippet I did
before, but then add a second stage where you reverse which is the catalog
and which is the coordinate to match.  Then only accept the pairs where
*both* directions agree on which is the closest neighbor.

If anyone wants to take up adding methods for one-to-one matching to
SkyCoord, feel free to try to implement that and issue a PR.  Or if you
want to dig deeper (for more memory efficiency), you can try using the
implementation of match_to_catalog_* or search_around_* as guides for what
to do.  Feel free to contact me if you have any questions about how to do
this.



On Fri, Jul 11, 2014 at 11:28 PM, Guang Yang <yg1991 at mail.ustc.edu.cn>
wrote:

> > As for the "matching mode", the idea is that there are a lot of
> > different "modes" people use, and match_to_catalog_sky (or
> > match_to_catalog_3d) along with the `nthneighbor` argument should be
> > flexible enough to take care of most of them.  Can you be more
> > specific about exactly what sort of mode you think is missing?
>
> Thanks for your response.
>
> In fact, we *often* use one-one match. In the code you give, there might
> be repetitive elements in 'catalogwithmatches'.  For example, for source A
> in 'catalog' there might be source B & C in 'coordstomatch' that both
> satisfy the criterion 'd2d < 3*u.arcmin'.  In this case, we want to pick up
> only the nearest one, say if distance A_B < A_C, we only regard A_B as real
> match.
>
> Though only several lines can carry it out, it's so frequently used that I
> think it should be a part of astropy.
>
> best wishes,
> guang
>
> > -----Original email-----
> > From: "Erik Tollerud" <erik.tollerud at gmail.com>
> > Sent Time: Jul 12, 2014 5:05:07 AM
> > To: "Astronomical Python mailing list" <astropy at scipy.org>
> > Cc: "Guang Yang" <yg1991 at mail.ustc.edu.cn>
> > Subject: Re: [AstroPy] Some Feedbacks about Astropy
> >
> > > 2. Though there's astropy.coordinates.matching.match_coordinates_sky
> to cross-correlate two catalogs, it doesn't allow user to specify matching
> radius and matching mode (e.g., one-one match). I've made a function to do
> so, and hope similar function can be included in astropy (
> https://github.com/Guang91/Astronomers_Tool_Box/blob/master/my_srcor.py).
> >
> > The idea is to use it like this (this is astropy 0.4 syntax - for
> > astropy 0.3 it's similar, but replace SkyCoord with `ICRS` or whatever
> > class makes sense for your coordinates):
> >
> > catalog = SkyCoord(ra_cat*u.deg, dec_cat*u.deg, frame='icrs')
> > coordstomatch = SkyCoord(ra*u.deg, dec*u.deg, frame='icrs')
> >
> > idx, d2d, d3d = coordstomatch.match_to_catalog_sky(catalog)
> >
> > coordinateswithmatches = coordstomatch[d2d < 3*u.arcmin]
> > catalogwithmatches = catalog[idx[d2d < 3*u.arcmin]]
> >
> >
> > As for the "matching mode", the idea is that there are a lot of
> > different "modes" people use, and match_to_catalog_sky (or
> > match_to_catalog_3d) along with the `nthneighbor` argument should be
> > flexible enough to take care of most of them.  Can you be more
> > specific about exactly what sort of mode you think is missing?
> >
> >
> > This was not too thoroughly documented before v0.4 (the version about
> > to be release), but there's a lot more there in v0.4. See
> > http://devdocs.astropy.org/coordinates/matchsep.html#matching-catalogs
> > (that's the developer documentation, but this will become
> >
> http://docs.astropy.org/en/stable/coordinates/matchsep.html#matching-catalogs
> > when 0.4 is released).
> >
> >
> >
> > --
> > Erik T
>
>


-- 
Erik T
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From ewald.zietsman at gmail.com  Thu Sep 25 09:37:06 2014
From: ewald.zietsman at gmail.com (Ewald Zietsman)
Date: Thu, 25 Sep 2014 15:37:06 +0200
Subject: [AstroPy] Fast(er) Deeming Periodograms from python via OpenCL
Message-ID: <CAMzebNnHYxZwxRFFGPkkEAXs6fWSEyOGCR4Sr+h-qVO1ub2xfA@mail.gmail.com>

Hi All,

I'm working with some Kepler data from which I need to extract amplitudes
and frequencies. The dataset is really long and hence the required DFT
takes an awfully long time to calculate (16 hours per DFT if I run 4
threads on my Macbook Pro). I'm getting around this problem by running it
in parallel on my Graphics Processing Unit (on my Linux Box) via PyopenCL.
I did a blog post about the kind of performance increase I get on my setup
doing this. You can read it here:

http://ezietsman.github.io/python/2014/09/06/parallel-python-on-a-gpu-with-opencl/

TL;DR; My Macbook will take around 16 hours to do one DFT which my will
take my GPU about 50 minutes.

I'm also working on a smallish library that will allow me to find and
prewhiten the lightcurve using robust sinusoid fitting after finding
amplitudes/periods using DFTs. That repo is still an infant and will change
quickly but it is here:

https://github.com/ezietsman/seismo

It at least shows (in the tests/ folder) how to run my DFT code. There are
3 DFT implementations at the moment, all three using exactly the same slow
algorithm, numpy serial, numpy/fortran/openmp parallel and opencl parallel.

I could work towards getting the numpy serial version into astropy somehow,
it there is interest?

Cheers!
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From thomas.robitaille at gmail.com  Mon Sep 29 07:45:19 2014
From: thomas.robitaille at gmail.com (Thomas Robitaille)
Date: Mon, 29 Sep 2014 13:45:19 +0200
Subject: [AstroPy] IAU Commission for Astronomical Software?
Message-ID: <CAGMHX_0PSkbwxbU7SZ38hup-tKOgRVYK3AQQeiqTnXZTH_cLng@mail.gmail.com>

Hi everyone,

A little while ago, the IAU put out a call for proposals for new
commissions for the IAU. As you will notice here:

http://www.iau.org/science/scientific_bodies/commissions/

there are commissions on data and documentation, but there are
surprisingly no commissions on software! (this was brought to my
attention by Stephen Serjeant from the Open University).

My question is the following: is anyone here leading or aware of
anyone leading a proposal for a software commission?

In case no one has already started this, I have created a google group
that you can sign up to if you are interested in helping out with such
an effort:

https://groups.google.com/forum/#!forum/iau-software-commission-proposal

I am not an IAU member so I will not be able to lead this proposal,
but I would be interested in helping out if someone here wants to take
the lead!

Cheers,
Tom


From teuben at astro.umd.edu  Mon Sep 29 08:00:06 2014
From: teuben at astro.umd.edu (Peter Teuben)
Date: Mon, 29 Sep 2014 08:00:06 -0400
Subject: [AstroPy] IAU Commission for Astronomical Software?
In-Reply-To: <CAGMHX_0PSkbwxbU7SZ38hup-tKOgRVYK3AQQeiqTnXZTH_cLng@mail.gmail.com>
References: <CAGMHX_0PSkbwxbU7SZ38hup-tKOgRVYK3AQQeiqTnXZTH_cLng@mail.gmail.com>
Message-ID: <542949C6.5030303@astro.umd.edu>

Hi All

I presume this issue will come up at ADASS next week, I had "sort of"
assumed
it would be absorbed in Comm.5 , which is about Data and Libraries.  Some
software (SOFA) was already part of this body (but not in Libraries, where
they mean the other overloaded paper thing).

In another group (theory/modeliing) I also overheard a desire to
organize software,
so hopefully this will not cause us to have two groups of software.

Of course the ASCL would be very interested in this as well, but that's
a given.

So, those at ADASS next week will hear more, and I suppose we'll report
back here

peter


On 09/29/2014 07:45 AM, Thomas Robitaille wrote:
> Hi everyone,
>
> A little while ago, the IAU put out a call for proposals for new
> commissions for the IAU. As you will notice here:
>
> http://www.iau.org/science/scientific_bodies/commissions/
>
> there are commissions on data and documentation, but there are
> surprisingly no commissions on software! (this was brought to my
> attention by Stephen Serjeant from the Open University).
>
> My question is the following: is anyone here leading or aware of
> anyone leading a proposal for a software commission?
>
> In case no one has already started this, I have created a google group
> that you can sign up to if you are interested in helping out with such
> an effort:
>
> https://groups.google.com/forum/#!forum/iau-software-commission-proposal
>
> I am not an IAU member so I will not be able to lead this proposal,
> but I would be interested in helping out if someone here wants to take
> the lead!
>
> Cheers,
> Tom
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy



From astropy at liska.ath.cx  Mon Sep 29 08:10:39 2014
From: astropy at liska.ath.cx (Ole Streicher)
Date: Mon, 29 Sep 2014 14:10:39 +0200
Subject: [AstroPy] IAU Commission for Astronomical Software?
References: <CAGMHX_0PSkbwxbU7SZ38hup-tKOgRVYK3AQQeiqTnXZTH_cLng@mail.gmail.com>
	<542949C6.5030303@astro.umd.edu>
Message-ID: <8761g6aaps.fsf@baikal.ole.ath.cx>

Hi all,

I'd be interested as well, mainly for coordination of
distribution/packaging issues between different platforms.

However, I will not be at ADASS this year, and I am also not an IAU
member.

Best regards

Ole

Peter Teuben <teuben at astro.umd.edu> writes:
> Hi All
>
> I presume this issue will come up at ADASS next week, I had "sort of"
> assumed
> it would be absorbed in Comm.5 , which is about Data and Libraries.  Some
> software (SOFA) was already part of this body (but not in Libraries, where
> they mean the other overloaded paper thing).
>
> In another group (theory/modeliing) I also overheard a desire to
> organize software,
> so hopefully this will not cause us to have two groups of software.
>
> Of course the ASCL would be very interested in this as well, but that's
> a given.
>
> So, those at ADASS next week will hear more, and I suppose we'll report
> back here
>
> peter
>
>
> On 09/29/2014 07:45 AM, Thomas Robitaille wrote:
>> Hi everyone,
>>
>> A little while ago, the IAU put out a call for proposals for new
>> commissions for the IAU. As you will notice here:
>>
>> http://www.iau.org/science/scientific_bodies/commissions/
>>
>> there are commissions on data and documentation, but there are
>> surprisingly no commissions on software! (this was brought to my
>> attention by Stephen Serjeant from the Open University).
>>
>> My question is the following: is anyone here leading or aware of
>> anyone leading a proposal for a software commission?
>>
>> In case no one has already started this, I have created a google group
>> that you can sign up to if you are interested in helping out with such
>> an effort:
>>
>> https://groups.google.com/forum/#!forum/iau-software-commission-proposal
>>
>> I am not an IAU member so I will not be able to lead this proposal,
>> but I would be interested in helping out if someone here wants to take
>> the lead!
>>
>> Cheers,
>> Tom
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy


From lucas.guibert at viacesi.fr  Mon Sep 29 13:47:26 2014
From: lucas.guibert at viacesi.fr (GUIBERT LUCAS)
Date: Mon, 29 Sep 2014 17:47:26 +0000
Subject: [AstroPy] Astropy on web
Message-ID: <1412012845921.51488@viacesi.fr>

Good morning incredible developers.


I just start an intership at UCLA and I have to work on a migration of a python software to a web python software. I don't have a lot of knowledge on web python but before doing anything else I prefer to be sure of a thing. Does Astropy will work with a web python framework like Django ? If it's yes, that will be more than very great! If it's no, that will be more than very bad...


Thanks for reading this.


Best regards,


Lucas Guibert.

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From aldcroft at head.cfa.harvard.edu  Mon Sep 29 14:09:04 2014
From: aldcroft at head.cfa.harvard.edu (Aldcroft, Thomas)
Date: Mon, 29 Sep 2014 14:09:04 -0400
Subject: [AstroPy] Astropy on web
In-Reply-To: <1412012845921.51488@viacesi.fr>
References: <1412012845921.51488@viacesi.fr>
Message-ID: <CAMtEP6xP+oskaY2QarnOBXOz1f8PzwGOrhuVd5q9sqd+vTHBbg@mail.gmail.com>

I use astropy in a Django web framework.  That is no problem at all.  The
only issue is related to the astropy configuration file which is required.
When running in a production environment (e.g. with Apache) this can be
handled with the $XDG_CONFIG_HOME environment variable.  See:

http://astropy.readthedocs.org/en/latest/config/index.html

- Tom

On Mon, Sep 29, 2014 at 1:47 PM, GUIBERT LUCAS <lucas.guibert at viacesi.fr>
wrote:

>  Good morning incredible developers.
>
>
>  I just start an intership at UCLA and I have to work on a migration of a
> python software to a web python software. I don't have a lot of knowledge
> on web python but before doing anything else I prefer to be sure of a
> thing. Does Astropy will work with a web python framework like Django ? If
> it's yes, that will be more than very great! If it's no, that will be more
> than very bad...
>
>
>  Thanks for reading this.
>
>
>  Best regards,
>
>
>  Lucas Guibert.
>
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>
>
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