[Matrix-SIG] Re: AstroPy ... Re: Data Analysis

Scott M. Ransom ransom@cfa.harvard.edu
Sun, 14 Feb 1999 17:27:47 +0000

For the Matrix-Sig people out there that have not subscribed to the AstroPy
mailing list, this is a reply to a post about creating an Astronomy related
data-analysis toolkit with Python.  I have cross-posted it because I think it
is relevant to the "new" data analysis effort....

W.T. Bridgman wrote:

> 1) One of the first tasks for this project is to find out what has already
> been done by list members.

I have made a couple small packages which might be of use to the Astro/Data
Analysis community (and I am more than willing to help out in any way I

1.  A Romberg Integrator and a "Safe" Newton-Raphson (both in pure Python)
that I wrote, are available as part of Konrad Hinson's Scientific Python

2.  I have written a Python wrapper for Nick Patavalis' very nice set of
PGPLOT wrappers.  The Python wrapper lets you make very nice plots (including
2-D images) with a single interactive call (ala IDL or MATLAB).  Both the
wrapper and Nick's package are available at:

3.  Not by me, but very useful nonetheless, Gary Strangman has made a very
complete (although I do not know how well it has been tested) set of
statistics functions available at:

4.  I have interfaced a large pulsar data analysis package that I wrote with
Python using SWIG.  I therefore have a fairly workable NumPy typemap file
(that will probably need to be edited quite extensively for general use) that
allows NumPy to use C arrays and vise-versa.  If anyone wants to use this as a
starting point for a more robust typemap, I have placed it in the above FTP

A couple other points:

I have been considering wrapping the 'C' version of SLALIB for Python.
Unfortunately, the author, P.T.Wallace (ptw@star.rl.ac.uk), only makes the 'C'
version available by email.  If we truly want this wrapped, we need to get his
permission and hopefully a method of making the most current 'C' version
available to anyone.  Does anyone know Mr. Wallace?  If not I might try to
email him myself about this.

I believe the most important thing that needs to be done (and this applies to
the Matrix group as well) is to develop a publication qualtiy (fonts
especially), portable, 2-D and 3-D surface/mesh plotting routine or library.
PGPLOT is great for 2-D work for astronomy, and the Gist stuff is nice as
well, but the font support (I believe) is not there (correct me if I'm wrong),
but I think we have to go beyond those.  The PerlDL people have a good start
on a workable OpenGL 3-D plotting package if some Perl guru out there has a
mind to start a porting effort.  Other options could be a much expanded
TkPlotCanvas, or the new Java APIs (including Java3D).

We should probably try to keep this tied in as much as possible with the
current effort, started by Joe Harrington and others on Matrix-Sig, to create
a full-blown data-analysis environment.



Scott M. Ransom
Phone:  (580) 536-7215             Address:  703 SW Chaucer Cir.
email:  ransom@cfa.harvard.edu               Lawton, OK  73505
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