From thomas.robitaille at gmail.com  Thu Feb  2 08:09:15 2017
From: thomas.robitaille at gmail.com (Thomas Robitaille)
Date: Thu, 2 Feb 2017 13:09:15 +0000
Subject: [AstroPy] Help with APLpy
In-Reply-To: <CAOuapOqZjhci_wR8pRNgkdzKn2gL75bLWtmO-chwJCiuCS5mTg@mail.gmail.com>
References: <CAOuapOqZjhci_wR8pRNgkdzKn2gL75bLWtmO-chwJCiuCS5mTg@mail.gmail.com>
Message-ID: <CAGMHX_38benHSvhP1mV-Qzyqg3Diqp16g+Ku5-oqsSFvWcXcbg@mail.gmail.com>

Hi Chika,

The make_rgb_image function takes a number of arguments to control the
brightness of each band:

http://aplpy.readthedocs.io/en/stable/api/aplpy.make_rgb_image.html#aplpy.make_rgb_image

e.g. vmin_r, vmax_r and so on.

Cheers,
Tom


On 1 February 2017 at 08:51, Chika Chukwuemeka <chikachukwuemeka at gmail.com>
wrote:

> Hello,
>
> I successfully made a composite-band image of a WISE YSO source using the
> make-RGB command in APLpy. However, the source i needed to mark is barely
> visible. How do I change the relative intensities of the different bands in
> order to bring it out more clearly? I guess it's the blue band which needs
> turning up a little.
>
> Reagards,
> Chika
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/astropy/attachments/20170202/c1ba97d1/attachment.html>

From hodge at stsci.edu  Thu Feb  2 11:12:30 2017
From: hodge at stsci.edu (Phil Hodge)
Date: Thu, 2 Feb 2017 11:12:30 -0500
Subject: [AstroPy] Help with APLpy
In-Reply-To: <CAGMHX_38benHSvhP1mV-Qzyqg3Diqp16g+Ku5-oqsSFvWcXcbg@mail.gmail.com>
References: <CAOuapOqZjhci_wR8pRNgkdzKn2gL75bLWtmO-chwJCiuCS5mTg@mail.gmail.com>
 <CAGMHX_38benHSvhP1mV-Qzyqg3Diqp16g+Ku5-oqsSFvWcXcbg@mail.gmail.com>
Message-ID: <9817661b-472b-cf51-84a0-937e9e428bf2@stsci.edu>

Just FYI, this looks like a typo in the docs:

*pmin_r, pmin_r, pmin_g* : float, optional

Phil

On 02/02/2017 08:09 AM, Thomas Robitaille wrote:
> Hi Chika,
>
> The make_rgb_image function takes a number of arguments to control the 
> brightness of each band:
>
> http://aplpy.readthedocs.io/en/stable/api/aplpy.make_rgb_image.html#aplpy.make_rgb_image
>
> e.g. vmin_r, vmax_r and so on.
>
> Cheers,
> Tom
>
>
> On 1 February 2017 at 08:51, Chika Chukwuemeka 
> <chikachukwuemeka at gmail.com <mailto:chikachukwuemeka at gmail.com>> wrote:
>
>     Hello,
>
>     I successfully made a composite-band image of a WISE YSO source
>     using the make-RGB command in APLpy. However, the source i needed
>     to mark is barely visible. How do I change the relative
>     intensities of the different bands in order to bring it out more
>     clearly? I guess it's the blue band which needs turning up a little.
>
>     Reagards,
>     Chika
>
>
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> https://mail.scipy.org/mailman/listinfo/astropy



From parejkoj at uw.edu  Thu Feb  2 12:47:44 2017
From: parejkoj at uw.edu (John K. Parejko)
Date: Thu, 2 Feb 2017 09:47:44 -0800
Subject: [AstroPy] Help with APLpy
In-Reply-To: <CAGMHX_38benHSvhP1mV-Qzyqg3Diqp16g+Ku5-oqsSFvWcXcbg@mail.gmail.com>
References: <CAOuapOqZjhci_wR8pRNgkdzKn2gL75bLWtmO-chwJCiuCS5mTg@mail.gmail.com>
 <CAGMHX_38benHSvhP1mV-Qzyqg3Diqp16g+Ku5-oqsSFvWcXcbg@mail.gmail.com>
Message-ID: <49225EA8-277D-47B7-BB24-F96914921A1B@uw.edu>

Though it?s not APLpy, you could try astropy.visualization.make_lupton_rgb (just added in astropy v1.3):

http://docs.astropy.org/en/stable/visualization/lupton_rgb.html

If you increase the Q parameter, and play with stretch, you might get something that remains astrophysically consistent, while still showing your source of interest. Note that it requires the images be aligned, but you should be able to pass in the results from aplpy?s reprojection.

John

> On 2Feb 2017, at 05:09, Thomas Robitaille <thomas.robitaille at gmail.com> wrote:
> 
> Hi Chika,
> 
> The make_rgb_image function takes a number of arguments to control the brightness of each band:
> 
> http://aplpy.readthedocs.io/en/stable/api/aplpy.make_rgb_image.html#aplpy.make_rgb_image
> 
> e.g. vmin_r, vmax_r and so on.
> 
> Cheers,
> Tom
> 
> 
> On 1 February 2017 at 08:51, Chika Chukwuemeka <chikachukwuemeka at gmail.com> wrote:
> Hello,
> 
> I successfully made a composite-band image of a WISE YSO source using the make-RGB command in APLpy. However, the source i needed to mark is barely visible. How do I change the relative intensities of the different bands in order to bring it out more clearly? I guess it's the blue band which needs turning up a little.
> 
> Reagards,
> Chika
> 
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> https://mail.scipy.org/mailman/listinfo/astropy



From boada at physics.rutgers.edu  Thu Feb  2 15:52:50 2017
From: boada at physics.rutgers.edu (Steven Boada)
Date: Thu, 2 Feb 2017 15:52:50 -0500
Subject: [AstroPy] Help with APLpy
In-Reply-To: <49225EA8-277D-47B7-BB24-F96914921A1B@uw.edu>
References: <CAOuapOqZjhci_wR8pRNgkdzKn2gL75bLWtmO-chwJCiuCS5mTg@mail.gmail.com>
 <CAGMHX_38benHSvhP1mV-Qzyqg3Diqp16g+Ku5-oqsSFvWcXcbg@mail.gmail.com>
 <49225EA8-277D-47B7-BB24-F96914921A1B@uw.edu>
Message-ID: <ae089605-b01d-de3d-580d-5343da300c3b@physics.rutgers.edu>

I'd like to mention that I had some images where making an RGB image 
particularly difficult. I played with APLpy and the make_lupton_rgb 
function in astropy withvery poor results.

I ended up using STIFF to make some very good looking three color 
images. I would have much preferred to use python exclusively, but I 
just couldn't get something that I liked.

Check out STIFF, if you are still having trouble.

Cheers.

steven

On 02/02/2017 12:47 PM, John K. Parejko wrote:
> Though it?s not APLpy, you could try astropy.visualization.make_lupton_rgb (just added in astropy v1.3):
>
> http://docs.astropy.org/en/stable/visualization/lupton_rgb.html
>
> If you increase the Q parameter, and play with stretch, you might get something that remains astrophysically consistent, while still showing your source of interest. Note that it requires the images be aligned, but you should be able to pass in the results from aplpy?s reprojection.
>
> John
>
>> On 2Feb 2017, at 05:09, Thomas Robitaille <thomas.robitaille at gmail.com> wrote:
>>
>> Hi Chika,
>>
>> The make_rgb_image function takes a number of arguments to control the brightness of each band:
>>
>> http://aplpy.readthedocs.io/en/stable/api/aplpy.make_rgb_image.html#aplpy.make_rgb_image
>>
>> e.g. vmin_r, vmax_r and so on.
>>
>> Cheers,
>> Tom
>>
>>
>> On 1 February 2017 at 08:51, Chika Chukwuemeka <chikachukwuemeka at gmail.com> wrote:
>> Hello,
>>
>> I successfully made a composite-band image of a WISE YSO source using the make-RGB command in APLpy. However, the source i needed to mark is barely visible. How do I change the relative intensities of the different bands in order to bring it out more clearly? I guess it's the blue band which needs turning up a little.
>>
>> Reagards,
>> Chika
>>
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> https://mail.scipy.org/mailman/listinfo/astropy
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> https://mail.scipy.org/mailman/listinfo/astropy

-- 

Steven Boada

Postdoctoral Researcher
Rutgers University
boada at physics.rutgers.edu



From dburke.gw at gmail.com  Mon Feb  6 08:50:03 2017
From: dburke.gw at gmail.com (Doug Burke)
Date: Mon, 06 Feb 2017 13:50:03 +0000
Subject: [AstroPy] ANN: Sherpa v4.9.0 released
Message-ID: <CALkjVLDFBG-+JVb_O1uc0dX20eo5Gw3HuNhuUTCygrUxb3qdDw@mail.gmail.com>

Dear colleagues,

We are very happy to announce the v4.9.0 release of Sherpa, a Python-based
fitting and modelling system that has strong support for Astronomy data (in
particular, X-ray data). Thanks to Zenodo and GitHub its DOI is
http://dx.doi.org/10.5281/zenodo.260416

Thanks to members of the AstroPy community, both for the packages we use in
Sherpa and for their investment in time reporting issues, suggesting fixes,
and providing code improvements. Development continues at
https://github.com/sherpa/sherpa/ and we welcome your continued interest.

Release notes are available at
https://github.com/sherpa/sherpa/releases/tag/4.9.0 and include improved
Python 3.5 support, a significant refactoring of the Fit and Stat classes
based on dicussions with our GammaPy colleagues, and a release to PyPi
https://pypi.python.org/pypi/sherpa/4.9.0

We provide Linux and OS-X packages for users of the Anaconda Python
Distribution,

$ conda config --add channels https://conda.binstar.org/sherpa
$ conda install sherpa

Or source code can be downloaded from https://github.com/sherpa/sherpa/tags

Further information can be found at http://cxc.harvard.edu/contrib/sherpa/
and we look forward to any input you have. Please feel free to forward this
announcement to anyone who you feel would be interested in this release.

For the Sherpa core development team,
Doug Burke
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/astropy/attachments/20170206/23ed1aa1/attachment.html>

From aszary at gmail.com  Wed Feb  8 10:40:07 2017
From: aszary at gmail.com (Andrzej Szary)
Date: Wed, 8 Feb 2017 16:40:07 +0100
Subject: [AstroPy] Ellipse2D fit
Message-ID: <CAOGYrkXrsAhLfdjyLjUPEQk_aYTkwD9Dn6UZOhbZgo4iaMfBAw@mail.gmail.com>

Hello,

I am struggling with  fitting an ellipse using Ellipse2D model. The fitting
procedure does not seem to have any effect on ellipse parameters (maybe
except amplitude).

Please find a test code at the end of this email.

Best wishes,
Andrzej Szary


import numpy as np
from astropy.modeling import models, fitting
import matplotlib.pyplot as pl

# data
num = 100
x, y = np.meshgrid(np.linspace(-5., 5., num), np.linspace(-5, 5, num))
e0 = models.Ellipse2D(amplitude=1., x_0=0., y_0=0., a=2, b=1, theta=0.)
z0 = e0(x, y)
print 'DATA:\n', e0, '\n\n'

# initial model
ei = models.Ellipse2D(amplitude=1., x_0=0.1, y_0=0.1, a=3, b=2, theta=0.2)
fi = fitting.LevMarLSQFitter()

# fitted model?
e1 = fi(ei, x, y, z0)
z1 = e1(x, y)
print 'MODEL:\n', e1, '\n\n'

pl.imshow(z0, extent=[-5, 5, -5, 5], alpha=0.5)
pl.imshow(z1, extent=[-5, 5, -5, 5], alpha=0.2)
pl.show()
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/astropy/attachments/20170208/dd96824c/attachment.html>

From fabricio.ferrari at gmail.com  Wed Feb 15 07:14:49 2017
From: fabricio.ferrari at gmail.com (Fabricio Ferrari)
Date: Wed, 15 Feb 2017 10:14:49 -0200
Subject: [AstroPy] AstroPy Digest, Vol 125, Issue 4
In-Reply-To: <mailman.3.1486641602.14543.astropy@scipy.org>
References: <mailman.3.1486641602.14543.astropy@scipy.org>
Message-ID: <CAKzpUfbq4mLbtr2MzP_8TJ+FvJm+f=DSSMRe4qqVTv8d5V4mPQ@mail.gmail.com>

Dear Andrzej

here it seemed to work. Maybe the version you are using.

Here I have:

In [2]: np.__version__
Out[2]: '1.11.1'

In [4]: astropy.__version__
Out[4]: u'1.2.1'


My output:


DATA:
Model: Ellipse2D
Inputs: (u'x', u'y')
Outputs: (u'z',)
Model set size: 1
Parameters:
    amplitude x_0 y_0  a   b  theta
    --------- --- --- --- --- -----
          1.0 0.0 0.0 2.0 1.0   0.0


MODEL:
Model: Ellipse2D
Inputs: (u'x', u'y')
Outputs: (u'z',)
Model set size: 1
Parameters:
      amplitude    x_0 y_0  a   b  theta
    -------------- --- --- --- --- -----
    0.338211382114 0.1 0.1 3.0 2.0   0.2




p.s. thank you for letting me know about the Ellipse2D fit, that I indeed
need and did not know about.

Regards

Fabricio



..-. ..-.
Fabricio Ferrari       [www.ferrari.pro.br]
IMEF -  FURG
Rio Grande, RS
Brasil

2017-02-09 10:00 GMT-02:00 <astropy-request at scipy.org>:

> Send AstroPy mailing list submissions to
>         astropy at scipy.org
>
> To subscribe or unsubscribe via the World Wide Web, visit
>         https://mail.scipy.org/mailman/listinfo/astropy
> or, via email, send a message with subject or body 'help' to
>         astropy-request at scipy.org
>
> You can reach the person managing the list at
>         astropy-owner at scipy.org
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of AstroPy digest..."
>
>
> Today's Topics:
>
>    1. Ellipse2D fit (Andrzej Szary)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 8 Feb 2017 16:40:07 +0100
> From: Andrzej Szary <aszary at gmail.com>
> To: astropy at scipy.org
> Subject: [AstroPy] Ellipse2D fit
> Message-ID:
>         <CAOGYrkXrsAhLfdjyLjUPEQk_aYTkwD9Dn6UZOhbZgo4iaMfBAw@
> mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> Hello,
>
> I am struggling with  fitting an ellipse using Ellipse2D model. The fitting
> procedure does not seem to have any effect on ellipse parameters (maybe
> except amplitude).
>
> Please find a test code at the end of this email.
>
> Best wishes,
> Andrzej Szary
>
>
> import numpy as np
> from astropy.modeling import models, fitting
> import matplotlib.pyplot as pl
>
> # data
> num = 100
> x, y = np.meshgrid(np.linspace(-5., 5., num), np.linspace(-5, 5, num))
> e0 = models.Ellipse2D(amplitude=1., x_0=0., y_0=0., a=2, b=1, theta=0.)
> z0 = e0(x, y)
> print 'DATA:\n', e0, '\n\n'
>
> # initial model
> ei = models.Ellipse2D(amplitude=1., x_0=0.1, y_0=0.1, a=3, b=2, theta=0.2)
> fi = fitting.LevMarLSQFitter()
>
> # fitted model?
> e1 = fi(ei, x, y, z0)
> z1 = e1(x, y)
> print 'MODEL:\n', e1, '\n\n'
>
> pl.imshow(z0, extent=[-5, 5, -5, 5], alpha=0.5)
> pl.imshow(z1, extent=[-5, 5, -5, 5], alpha=0.2)
> pl.show()
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: <https://mail.scipy.org/pipermail/astropy/attachments/
> 20170208/dd96824c/attachment-0001.html>
>
> ------------------------------
>
> Subject: Digest Footer
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> https://mail.scipy.org/mailman/listinfo/astropy
>
>
> ------------------------------
>
> End of AstroPy Digest, Vol 125, Issue 4
> ***************************************
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/astropy/attachments/20170215/56114ebc/attachment.html>

From aszary at gmail.com  Wed Feb 15 07:47:39 2017
From: aszary at gmail.com (Andrzej Szary)
Date: Wed, 15 Feb 2017 13:47:39 +0100
Subject: [AstroPy] Ellipse2D fit
In-Reply-To: <CAOGYrkXrsAhLfdjyLjUPEQk_aYTkwD9Dn6UZOhbZgo4iaMfBAw@mail.gmail.com>
References: <CAOGYrkXrsAhLfdjyLjUPEQk_aYTkwD9Dn6UZOhbZgo4iaMfBAw@mail.gmail.com>
Message-ID: <CAOGYrkXLYyOmg2MFyCBKZqfjBpBBOfswjH0MyaD9jM5ACkWQ=w@mail.gmail.com>

Dear Fabricio,

Note that the DATA and MODEL parameters are different. For a good fit they
should be similar. You can get better results using different fitter (*fi =
fitting.SimplexLSQFitter()*), but it is still not good enough for my
purpose (I need to find theta parameter).

Best wishes
Andrzej Szary


>> On 15 February 2017 at 13:14, Fabricio Ferrari <
fabricio.ferrari at gmail.com> wrote:
>>
>> Dear Andrzej
>>
>> here it seemed to work. Maybe the version you are using.
>>
>> Here I have:
>>
>>In [2]: np.__version__
>>Out[2]: '1.11.1'
>>
>>In [4]: astropy.__version__
>>Out[4]: u'1.2.1'
>>
>>My output:
>>
>>DATA:
>>Model: Ellipse2D
>>Inputs: (u'x', u'y')
>>Outputs: (u'z',)
>>Model set size: 1
>>Parameters:
>>    amplitude x_0 y_0  a   b  theta
>>    --------- --- --- --- --- -----
>>          1.0 0.0 0.0 2.0 1.0   0.0
>>
>>
>>MODEL:
>>Model: Ellipse2D
>>Inputs: (u'x', u'y')
>>Outputs: (u'z',)
>>Model set size: 1
>>Parameters:
>>      amplitude    x_0 y_0  a   b  theta
>>    -------------- --- --- --- --- -----
>>    0.338211382114 0.1 0.1 3.0 2.0   0.2
>>
>>p.s. thank you for letting me know about the Ellipse2D fit, that I indeed
need and did not >>know about.
>>
>>Regards
>>Fabricio


On 8 February 2017 at 16:40, Andrzej Szary <aszary at gmail.com> wrote:

> Hello,
>
> I am struggling with  fitting an ellipse using Ellipse2D model. The
> fitting procedure does not seem to have any effect on ellipse parameters
> (maybe except amplitude).
>
> Please find a test code at the end of this email.
>
> Best wishes,
> Andrzej Szary
>
>
> import numpy as np
> from astropy.modeling import models, fitting
> import matplotlib.pyplot as pl
>
> # data
> num = 100
> x, y = np.meshgrid(np.linspace(-5., 5., num), np.linspace(-5, 5, num))
> e0 = models.Ellipse2D(amplitude=1., x_0=0., y_0=0., a=2, b=1, theta=0.)
> z0 = e0(x, y)
> print 'DATA:\n', e0, '\n\n'
>
> # initial model
> ei = models.Ellipse2D(amplitude=1., x_0=0.1, y_0=0.1, a=3, b=2, theta=0.2)
> fi = fitting.LevMarLSQFitter()
>
> # fitted model?
> e1 = fi(ei, x, y, z0)
> z1 = e1(x, y)
> print 'MODEL:\n', e1, '\n\n'
>
> pl.imshow(z0, extent=[-5, 5, -5, 5], alpha=0.5)
> pl.imshow(z1, extent=[-5, 5, -5, 5], alpha=0.2)
> pl.show()
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/astropy/attachments/20170215/99942b61/attachment.html>

From fabricio.ferrari at gmail.com  Wed Feb 15 08:07:53 2017
From: fabricio.ferrari at gmail.com (Fabricio Ferrari)
Date: Wed, 15 Feb 2017 11:07:53 -0200
Subject: [AstroPy] Ellipse2D fit
In-Reply-To: <CAOGYrkXLYyOmg2MFyCBKZqfjBpBBOfswjH0MyaD9jM5ACkWQ=w@mail.gmail.com>
References: <CAOGYrkXrsAhLfdjyLjUPEQk_aYTkwD9Dn6UZOhbZgo4iaMfBAw@mail.gmail.com>
 <CAOGYrkXLYyOmg2MFyCBKZqfjBpBBOfswjH0MyaD9jM5ACkWQ=w@mail.gmail.com>
Message-ID: <CAKzpUfbnckS=ukYx2kT6jYMYUjeJv7AXQROZ38rMGZS=xUi5eA@mail.gmail.com>

yes of course, I did not paid attention. sorry :-D


I have been using Fitzgibbon, Pilu and Fischer  solution for fitting
ellipses, which is states the problem such that it can be written as and
eigenvalue equation (it is not iterative). Please, take a look for example
at

http://nicky.vanforeest.com/misc/fitEllipse/fitEllipse.html

The original paper I think it is:
http://cseweb.ucsd.edu/~mdailey/Face-Coord/ellipse-specific-fitting.pdf

regards.

F

..-. ..-.
Fabricio Ferrari       [www.ferrari.pro.br]
IMEF -  FURG
Rio Grande, RS
Brasil

2017-02-15 10:47 GMT-02:00 Andrzej Szary <aszary at gmail.com>:

> Dear Fabricio,
>
> Note that the DATA and MODEL parameters are different. For a good fit they
> should be similar. You can get better results using different fitter (*fi
> = fitting.SimplexLSQFitter()*), but it is still not good enough for my
> purpose (I need to find theta parameter).
>
> Best wishes
> Andrzej Szary
>
>
> >> On 15 February 2017 at 13:14, Fabricio Ferrari <
> fabricio.ferrari at gmail.com> wrote:
> >>
> >> Dear Andrzej
> >>
> >> here it seemed to work. Maybe the version you are using.
> >>
> >> Here I have:
> >>
> >>In [2]: np.__version__
> >>Out[2]: '1.11.1'
> >>
> >>In [4]: astropy.__version__
> >>Out[4]: u'1.2.1'
> >>
> >>My output:
> >>
> >>DATA:
> >>Model: Ellipse2D
> >>Inputs: (u'x', u'y')
> >>Outputs: (u'z',)
> >>Model set size: 1
> >>Parameters:
> >>    amplitude x_0 y_0  a   b  theta
> >>    --------- --- --- --- --- -----
> >>          1.0 0.0 0.0 2.0 1.0   0.0
> >>
> >>
> >>MODEL:
> >>Model: Ellipse2D
> >>Inputs: (u'x', u'y')
> >>Outputs: (u'z',)
> >>Model set size: 1
> >>Parameters:
> >>      amplitude    x_0 y_0  a   b  theta
> >>    -------------- --- --- --- --- -----
> >>    0.338211382114 0.1 0.1 3.0 2.0   0.2
> >>
> >>p.s. thank you for letting me know about the Ellipse2D fit, that I
> indeed need and did not >>know about.
> >>
> >>Regards
> >>Fabricio
>
>
> On 8 February 2017 at 16:40, Andrzej Szary <aszary at gmail.com> wrote:
>
>> Hello,
>>
>> I am struggling with  fitting an ellipse using Ellipse2D model. The
>> fitting procedure does not seem to have any effect on ellipse parameters
>> (maybe except amplitude).
>>
>> Please find a test code at the end of this email.
>>
>> Best wishes,
>> Andrzej Szary
>>
>>
>> import numpy as np
>> from astropy.modeling import models, fitting
>> import matplotlib.pyplot as pl
>>
>> # data
>> num = 100
>> x, y = np.meshgrid(np.linspace(-5., 5., num), np.linspace(-5, 5, num))
>> e0 = models.Ellipse2D(amplitude=1., x_0=0., y_0=0., a=2, b=1, theta=0.)
>> z0 = e0(x, y)
>> print 'DATA:\n', e0, '\n\n'
>>
>> # initial model
>> ei = models.Ellipse2D(amplitude=1., x_0=0.1, y_0=0.1, a=3, b=2, theta=0.2)
>> fi = fitting.LevMarLSQFitter()
>>
>> # fitted model?
>> e1 = fi(ei, x, y, z0)
>> z1 = e1(x, y)
>> print 'MODEL:\n', e1, '\n\n'
>>
>> pl.imshow(z0, extent=[-5, 5, -5, 5], alpha=0.5)
>> pl.imshow(z1, extent=[-5, 5, -5, 5], alpha=0.2)
>> pl.show()
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/astropy/attachments/20170215/c29cf1e2/attachment.html>

From alexandre.beelen at ias.u-psud.fr  Thu Feb 16 03:39:06 2017
From: alexandre.beelen at ias.u-psud.fr (Alexandre Beelen)
Date: Thu, 16 Feb 2017 09:39:06 +0100
Subject: [AstroPy] VO cone-searches
Message-ID: <8f7c30d6-74dd-c096-6e3d-d5869cb33f88@ias.u-psud.fr>

Hi,

Following the documentation [1], I was trying to use the 
~astropy.vo.client.vos_catalog.call_vo_service routine to make a 
conesearch on a list of services which are not present in the default 
cone search services list, namely a bunch of CDS/Vizier cone search 
services.

Using  vos_catalog.VOSCatalog I created a custom database with 3 
conesearch services, which I passed to vos_catalog.call_vo_service. 
However, only the first matching service result is returned, instead of 
the naively expected 3 results. It seems that this is a built-in feature 
of call_vo_service [2].

I was wondering if this was a wanted feature or if I could wrap-up a 
small PR to return a list of ~astropy.Table.table.

Similarly ~astroquery returns a custom 
~astroquery.utils.commons.TableList ordered list, but I wonder if the 
equivalent type exist or will exist in astropy.table.

Thanks !

a.

PS : BTW, would it be better to send an email here or to open an issue 
on github for this kind of problem ?


1 - http://docs.astropy.org/en/stable/vo/conesearch/client.html
2 - 
https://github.com/astropy/astropy/blob/master/astropy/vo/client/vos_catalog.py 
Line 871


From p3y1i4n at gmail.com  Fri Feb 17 12:31:56 2017
From: p3y1i4n at gmail.com (Pey Lian Lim)
Date: Fri, 17 Feb 2017 12:31:56 -0500
Subject: [AstroPy] VO cone-searches
Message-ID: <CAJt49iQ1kx5Q9=F2xjPObo_M+ntvxcWDyCHWsMvyNL-=+K=ORQ@mail.gmail.com>

Hi Alexandre,

Please open an issue on GitHub. Yes, it is indeed possible but maybe not
well advertised. Posting the answer on GitHub will also benefit others in
similar situation as yours.

The reason that it stops after first successful query is to avoid getting
too many unnecessary results, as theoretically you can give a list of
hundreds of services to try at once.

Thank you,
Pey-Lian (conesearch maintainer)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/astropy/attachments/20170217/a3232fd6/attachment.html>

From bruno.sanchez.63 at gmail.com  Tue Feb 21 13:52:47 2017
From: bruno.sanchez.63 at gmail.com (=?UTF-8?Q?Bruno_O=2E_S=C3=A1nchez?=)
Date: Tue, 21 Feb 2017 18:52:47 +0000
Subject: [AstroPy] Fitting a 2D Gaussian Model
Message-ID: <CACJJhJxGnNP5Oy5QFmw8h1bf26A+JJLKkFyszGoZjrncXNTdyQ@mail.gmail.com>

Hello!

I'm currently playing with the modeling module,
using models and fitting, and I have encountered difficulties
in how to understand the values of theta that the fit delivers.

I'm looping through several ellipticities, and I obtain theta angle values
that can bu up to a several hundred, even in negative values.

This is the code snippet to fit the gaussians is on this link.
http://dpaste.com/3HW8J4Y

The output I've got is pasted here:
http://dpaste.com/3SJ6DDP

Could someone help me to understand why is this happening?
As something intesting if I plot the true and fitted gaussian using
pyplot.imshow()
they look pretty similar.

Thanks!
-- 
Bruno
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/astropy/attachments/20170221/2e1ba435/attachment.html>

From larry.bradley at gmail.com  Tue Feb 21 15:42:40 2017
From: larry.bradley at gmail.com (Larry Bradley)
Date: Tue, 21 Feb 2017 15:42:40 -0500
Subject: [AstroPy] Fitting a 2D Gaussian Model
In-Reply-To: <CACJJhJxGnNP5Oy5QFmw8h1bf26A+JJLKkFyszGoZjrncXNTdyQ@mail.gmail.com>
References: <CACJJhJxGnNP5Oy5QFmw8h1bf26A+JJLKkFyszGoZjrncXNTdyQ@mail.gmail.com>
Message-ID: <CAFfmSa3BihD0gb38iZhAOjr6-f_m=5U4oThQEaUaBAYHxwt2rA@mail.gmail.com>

Hi Bruno,

The theta values in the model are not restricted to a particular range
(e.g. [0, 179] or [0, 359]).  What you are seeing are 180 degree
degeneracies of the Gaussian2D model with theta, e.g. theta = -625 is
identical to theta = 95 or theta = 275.

Also note that there is a more subtle 90 degree degeneracy with theta where
the x_stddev and y_stddev are flipped, e.g. x_stddev=10, y_stddev=5,
theta=0 is identical to x_stddev=5, y_stddev=10, theta=90.

Cheers,
Larry

On Tue, Feb 21, 2017 at 1:52 PM, Bruno O. S?nchez <
bruno.sanchez.63 at gmail.com> wrote:

> Hello!
>
> I'm currently playing with the modeling module,
> using models and fitting, and I have encountered difficulties
> in how to understand the values of theta that the fit delivers.
>
> I'm looping through several ellipticities, and I obtain theta angle values
> that can bu up to a several hundred, even in negative values.
>
> This is the code snippet to fit the gaussians is on this link.
> http://dpaste.com/3HW8J4Y
>
> The output I've got is pasted here:
> http://dpaste.com/3SJ6DDP
>
> Could someone help me to understand why is this happening?
> As something intesting if I plot the true and fitted gaussian using
> pyplot.imshow()
> they look pretty similar.
>
> Thanks!
> --
> Bruno
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> https://mail.scipy.org/mailman/listinfo/astropy
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/astropy/attachments/20170221/4bd0aa7c/attachment.html>

From parejkoj at uw.edu  Thu Feb 23 14:44:13 2017
From: parejkoj at uw.edu (John K. Parejko)
Date: Thu, 23 Feb 2017 12:44:13 -0700
Subject: [AstroPy] unit equivalency testing
Message-ID: <0BA1EB84-203C-44A1-8BFD-4AAE2DD2DBFA@uw.edu>

Hello astropy,

I?m looking for a way to check whether astropy units are ?convertible? to each other. For now, asking if the two units have the same physical type is a good start for me (which might be a handy utility method on a quantity: `quantity1.convertible_to(quantity2)`):

u.get_physical_type(quantity.unit) == u.get_physical_type(self.unit)

but I see that there?s a rich unit equivalency system available. What I?d like is something like `quantity1.equivalent_to(quantity2)`, that returns True/False whether those units are equivalent, based on the defined equivalencies of that unit. Is there such a feature available?

Thank you,
John



From adrianmpw at gmail.com  Thu Feb 23 14:57:48 2017
From: adrianmpw at gmail.com (Adrian Price-Whelan)
Date: Thu, 23 Feb 2017 14:57:48 -0500
Subject: [AstroPy] unit equivalency testing
In-Reply-To: <0BA1EB84-203C-44A1-8BFD-4AAE2DD2DBFA@uw.edu>
References: <0BA1EB84-203C-44A1-8BFD-4AAE2DD2DBFA@uw.edu>
Message-ID: <CAEUL7mHs9H76k0VcfoHcev5qh9TJg=Qw1BYSGC0NeazODhbDLg@mail.gmail.com>

I think what you want is "is_equivalent()":

>>> import astropy.units as u
>>> a = 15*u.kpc
>>> a.unit.is_equivalent(u.km)
True
>>> a = 15*u.Hz
>>> a.unit.is_equivalent(u.Angstrom, equivalencies=u.spectral())
True

Right now, it's just a method on UnitBase objects, but it might make
sense to add a convenience method on Quantity as well...

On Thu, Feb 23, 2017 at 2:44 PM, John K. Parejko <parejkoj at uw.edu> wrote:
> Hello astropy,
>
> I?m looking for a way to check whether astropy units are ?convertible? to each other. For now, asking if the two units have the same physical type is a good start for me (which might be a handy utility method on a quantity: `quantity1.convertible_to(quantity2)`):
>
> u.get_physical_type(quantity.unit) == u.get_physical_type(self.unit)
>
> but I see that there?s a rich unit equivalency system available. What I?d like is something like `quantity1.equivalent_to(quantity2)`, that returns True/False whether those units are equivalent, based on the defined equivalencies of that unit. Is there such a feature available?
>
> Thank you,
> John
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> https://mail.scipy.org/mailman/listinfo/astropy



-- 
Adrian M. Price-Whelan
Lyman Spitzer, Jr. Postdoctoral Fellow
Princeton University
http://adrian.pw


From parejkoj at uw.edu  Thu Feb 23 16:48:36 2017
From: parejkoj at uw.edu (John K. Parejko)
Date: Thu, 23 Feb 2017 14:48:36 -0700
Subject: [AstroPy] unit equivalency testing
In-Reply-To: <CAEUL7mHs9H76k0VcfoHcev5qh9TJg=Qw1BYSGC0NeazODhbDLg@mail.gmail.com>
References: <0BA1EB84-203C-44A1-8BFD-4AAE2DD2DBFA@uw.edu>
 <CAEUL7mHs9H76k0VcfoHcev5qh9TJg=Qw1BYSGC0NeazODhbDLg@mail.gmail.com>
Message-ID: <976E574F-9CA4-4E97-A4C9-FF362BFE2A9A@uw.edu>

Ah, perfect! I don?t know how I missed that. Thank you!

Making a convenience method on Quantity would be helpful. Heck, here?s a hastily-written PR that implements it:

https://github.com/astropy/astropy/pull/5836

John

> On 23Feb 2017, at 12:57, Adrian Price-Whelan <adrianmpw at gmail.com> wrote:
> 
> I think what you want is "is_equivalent()":
> 
>>>> import astropy.units as u
>>>> a = 15*u.kpc
>>>> a.unit.is_equivalent(u.km)
> True
>>>> a = 15*u.Hz
>>>> a.unit.is_equivalent(u.Angstrom, equivalencies=u.spectral())
> True
> 
> Right now, it's just a method on UnitBase objects, but it might make
> sense to add a convenience method on Quantity as well...
> 
> On Thu, Feb 23, 2017 at 2:44 PM, John K. Parejko <parejkoj at uw.edu> wrote:
>> Hello astropy,
>> 
>> I?m looking for a way to check whether astropy units are ?convertible? to each other. For now, asking if the two units have the same physical type is a good start for me (which might be a handy utility method on a quantity: `quantity1.convertible_to(quantity2)`):
>> 
>> u.get_physical_type(quantity.unit) == u.get_physical_type(self.unit)
>> 
>> but I see that there?s a rich unit equivalency system available. What I?d like is something like `quantity1.equivalent_to(quantity2)`, that returns True/False whether those units are equivalent, based on the defined equivalencies of that unit. Is there such a feature available?
>> 
>> Thank you,
>> John
>> 
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> https://mail.scipy.org/mailman/listinfo/astropy
> 
> 
> 
> -- 
> Adrian M. Price-Whelan
> Lyman Spitzer, Jr. Postdoctoral Fellow
> Princeton University
> http://adrian.pw
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> https://mail.scipy.org/mailman/listinfo/astropy