These are chat archives for astropy/astropy

9th
Jun 2014
Brigitta Sipocz
@bsipocz
Jun 09 2014 12:11
I'm wondering whether anyone can suggest a tool for this user case problem: I have time series data for small patches of the sky. There are several pointings with different exposure times, etc. I would like to make a plot with the cumulative exptime coverage of the field I'm looking at. What is the best tool to do that? I feel that my current idea is rather brute force, only slightly better than stacking all the images (a few thousand) together with exptime instead of flux data.
Stuart Mumford
@Cadair
Jun 09 2014 12:30
@bsipocz That's an interesting problem
I can't really think of a better solution than stacking all the individual time series and then compositing the stacked images.
Brigitta Sipocz
@bsipocz
Jun 09 2014 12:34
Yes, I thought it would be a pretty illustration in my thesis, but as always it's a bit more difficult to do it properly than in the original thought.
Stuart Mumford
@Cadair
Jun 09 2014 12:35
ha! I know that feeling!
the stacking of the images should be easy enough if you have arrays of exposure time?
you can just sum along the time axis?
I don't really know how you would do the second step though
It's not something I have to do! :D
Brigitta Sipocz
@bsipocz
Jun 09 2014 12:37
What you mean the time axis? The images are individual ones, and there may be a position shift between them even in the same series, and sometimes.
Stuart Mumford
@Cadair
Jun 09 2014 12:38
ahhhh that makes it even more complicated!!
Yeah I have no idea
Brigitta Sipocz
@bsipocz
Jun 09 2014 12:39
the brute force idea is to rewrite the data with the exptimes for each pixel, and then stack the images. I haven't tried it, but almost sure that it would kill our server if I use my current non-pythonic stacking tools.
Stuart Mumford
@Cadair
Jun 09 2014 12:40
yeah, I can't imagine a method that is easier than that
unless you can like re-grid your time series to make it less accurate but faster
Thomas Robitaille
@astrofrog
Jun 09 2014 19:36
So does anyone have any objections to merging astropy/astropy#2415
?