barnabytprowe/great3-public

Update required in example scripts due to change in galsim.Image() initialization syntax

Closed this issue · 7 comments

barnabytprowe commented

I think one or more of the example scripts might need updating in the light of recent changes to GalSim (specifically to the galsim.Image API: GalSim-developers/GalSim#495)

I know for a fact that coadd_multiepoch.py needs updating, because the following line (and those like it) is out of date:

    # Load full image array into an ImageF instance
    image = galsim.ImageViewF(
        pyfits.getdata(inprefix+"%03d-%1d.fits" % (field, 0)).astype(numpy.float32), scale=1.)

as the galsim.ImageViewF() way of initializing images has gone the way of the Dinosaur since GalSim-developers/GalSim#495 was merged in. I think that similar things may be found in the other codes, but part of this issue will see me check that.

My hacky solution is a try:, except: block:

    # Load full image array into an ImageF instance
    try:
        image = galsim.ImageViewF(
            pyfits.getdata(inprefix+"%03d-%1d.fits" % (field, 0)).astype(numpy.float32), scale=1.)
    except: # For those users who have a newer version of GalSim than v1.0.1...
        image = galsim.ImageF(
            pyfits.getdata(inprefix+"%03d-%1d.fits" % (field, 0)).astype(numpy.float32), scale=1.)

I generally don't like to use a bare except:, but to be honest there is very little else here that can be going wrong assuming that correct GREAT3 images are being used, so I don't think it is a real problem. (The Boost.Python-thrown exception claims to be an ArgumentError but this is not defined at the Python level. I don't think it's a big issue to use the catch-all as above for these simple, uni-purpose scripts. If it's a pyfits exception that was thrown in the first place, it will still trigger after the except: anyway.)

Comments welcome.

rmjarvis commented

Or, just say that all the great3-public stuff require galsim 1.0. I don't think anything in great3-public needs any of the new stuff that is currently on master.

barnabytprowe commented

That is true; it would require a minor documentation edit but that's it.

barnabytprowe commented

@rmandelb , @msimet , any objection to simply modifying the documentation for the example scripts to require GalSim v0.4-1.0 rather than GalSim 0.4+?

rmandelb commented

No objection at all!

rmjarvis commented

I would change it to 1.0, not 0.4-1.0. I believe there were bugs in the 0.4 and 0.5 versions that could be relevant, so best to encourage people to upgrade to 1.0 if they haven't already.

rmandelb commented

Good point. I agree. Also I believe the shear estimation codes have been optimized significantly since 0.4…

barnabytprowe commented

OK cool, I think I'll do this on master then close the issue.