[AstroPy] Co-ordinating Python astronomy libraries?

[Perry Greenfield]

I'd like to tackle the WCS issue first since there are already several  
flavors out there and I really wonder if that is necessary. Mike  
Droettboom is going to take a look at the others and see what the  
differences are in the next week. It would be good to get some  
convergence on that.

But I don't think that can stop others from surveying and comparing  
what is out there with regard to coordinates or time.

As far as the pure python aspect goes, I don't know if I would be so  
definitive on that. If there is already a good time or coordinates  
library in C that has been very well tested, it might make sense to  
use that. It isn't usually a big deal to distribute C code if it has  
no other dependencies. Fortran is a different issue. And there are  
many tricky issues with regard to coordinate systems. If reimplemented  
in  pure python I'd suggest that we do a exhaustive test comparison  
(mostly automatically generated if possible) with a well tested  
library to make sure that it was well validated.

Perry

On Jul 16, 2010, at 5:01 AM, Wolfgang Kerzendorf wrote:

>  Hello guys,
>
> I think astropysics looks like a very good start for the coordinate  
> class.
> As you said we should at the moment focus on having python-only  
> classes
> for the base-level. That makes it easy to distribute. Once a good API
> has been established and there's complaints about speed, we can switch
> over to c or fortran implementations with the same API.
>
> A monolithic distribution is not so good. I think these baselevel
> classes should, be very modular. We can probably achieve the best
> exceptance when these base classes are lean and mean. Like the unix
> tools, each one of them should only provide a very limited set of
> functionality. A good start might be pyAstroTime and pyAstroCoords or
> so. That's where raiding and plundering the existing code base comes  
> in.
> We can use some of Erik's and Brandon's stuff and others. I think we  
> can
> easily make a working prototype and the build from there.
>
> As suggested, we need to be careful not to ignore anyone. But I think
> that's easily done by making groups from this community, that take  
> care
> of a single implementation. Everyone who's interested in contributing,
> can join. That way the workload is shared and it is build by the
> community for the community.
>
> What do you guys think?
>
> Cheers
>     Wolfgang