[AstroPy] A simple python module, wrapping pytfits+matplotlib: fits I/O + graphic/display environment
emsellem at obs.univ-lyon1.fr
Fri May 5 11:49:27 CDT 2006
>> Image1.fits = Image2.fits / (Image3.fits + 3.4)
> This kind of syntax would not work in Python without some sort of
> special interpretation since Python would not find ImageX.fits in the
> current namespace. That means you have to think about what context you
> want this kind of capability to work in. As a special, non-Python
> command language that gets translated into python (pyraf does that for
> IRAF-like commands)?
yes indeed this was a puzzle I wanted to solve (include the potential of
a syntax interpretation) but did not know how to address. I will first
see if this is really necessary at this stage since it may a major
complication (for me).
> I suppose I would say the idea needs a bit more definition as to whether
> it is enhancement to python libraries or a new kind of shell.
agreed. I need to first work a little more on this, see what I really
need to develop and what I can just inherit from python+pyfits etc .
I guess I will have a try at it, send the whole thing with some examples
and wait for reactions...
> Yes, but this is a bad time for us at STScI for the next month or two
> (we are really spread thinly over several projects; hopefully it won't
> be so bad in a couple months)
> So I'd say that it would be hard for us to provide much help or even
> advice in the very short term.
well, it is always good to know there are experts around. I have waited
1 year so far to really start things. Waiting another number of months
is not a problem (the sooner the better, but this is only a "best
On May 4, 2006, at 6:56 PM, James Turner wrote:
>> If you would rather work with FITS files, I'm guessing it's for one of
>> three (good) reasons: 1) you want to save all your intermediate results
>> to disk, 2) you need to propagate headers, variance extensions etc.,
>Note that 2) is a common desire, but think about how easy it is in practice.
>When presented with two headers with conflicting header info, which does one use,
>the first, or some combination when adding two fits files? This is always much harder
>to do well in practice. Given the complex arrangements FITS files can have, I have my
>doubts about this being a really useful reason outside of doing very simple things
>(in essence, saying that one doesn't care that much about what is in the headers or
>how different entities are related in fits files)
agreed, If this is the way to go, we need CLEAR but also USEFUL! rules.
I already thought a little about this and there are simple cases we can
treat (as when we wish to do spec1 + spec2, where we check the step and
start - to see if these are concomitant - and then do the work on the
intersection only for example). Again, this has to be worth it.
and thanks for the warning about pyraf and ipython. Useful indeed. (but
I am not an Iraf fan here, as a practical tool I mean)
thanks a lot for the input.
Eric Emsellem emsellem at obs.univ-lyon1.fr
Centre de Recherche Astrophysique de Lyon
9 av. Charles-Andre tel: +33 (0)4 78 86 83 84
69561 Saint-Genis Laval Cedex fax: +33 (0)4 78 86 83 86
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