[AstroPy] POLL: vision for a common Astronomy package

[Brian Kloppenborg]

Greetings,

I have just recently joined the AstroPy listserv and am very happy to 
hear there is an effort to create a unified library for 
astronomy/astrophysics.  I openly welcome such a task and will be happy 
to contribute time coding the routines.

I am, however, a little concerned that the current vision statement 
seems to exclude the use of existing officially sanctioned (i.e. by the 
IAU) routines that are written in other languages.

For instance, the Standards of Fundamental Astronomy 
(http://www.iausofa.org/) package contains IAU-sanctioned routines for 
very common tasks (Calendards, Time Scales, Sidereal times, Ephemerids, 
star motion, star catalog conversion, etc).  This package is written in 
C and is quite easily wrapped using SWIG (see the pysofa package 
http://pypi.python.org/pypi/pysofa).  If the interface layer is 
implemented correctly, the function calls have minimal overhead and, in 
some circumstances, can benefit from being implemented in lower-level 
languages.

A quick example would be a general purpose library for common tasks in 
optical interferometry, in particular image reconstruction.  The code 
uses OpenCL which can leverage multiple CPUs and/or multiple GPUs to 
speed up the most time consuming tasks.  I've consistently demonstrated 
a 243x speed up over traditional CPU methods using the GPU and I really 
don't want to rewrite this in Python for inclusion in astropy.

Is there room for using libraries that are endorsed by a high-level 
governing body but that are written in other languages as a basis for 
some of astropy?  With the use of SWIG and official routines we could 
get (1) rapid development, (2) officially sanctioned routines that we 
don't have to debug/maintain, and (3) an interface to a well-developed 
package that we could enforce through the interface layer.  Clearly the 
detriment is that we would need to keep the packages in sync.  This is a 
common release problem in the programming world and has existing 
solutions though.

Thank you for your consideration,
Brian


On 06/30/2011 06:44 PM, Paul Barrett wrote:
> Since, it appears that this vision for an astropy suite will be
> adopted, given the overwhelming number of yeses at the current time,
> do you have a timeline in mind for how to proceed, i.e., what modules
> are being considered for the initial release and when will it occur?
>
>   -- Paul
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