John Parejko

### Description This pull request adds a simple PSF image to NDData/CCDData, to support the Rubin Observatory LSST Prompt Processing alert distribution system. The LSST alert packet image cutouts will...

Inconsistent piff log message levels

2

Under seemingly normal processing, piff outputs log messages that appear to have incorrect log levels. `warning` for the iteration numbers and total chi2, and `info` for statements about ill-conditioned matrices...

Piff catastrophically fails when PixelGrid size is larger than input star images

3

We are using Piff in Rubin processing, and have discovered that the model fit for a `size=25` `PixelGrid` catastrophically fails, without any clear indication of the error from Piff itself....

fits files not containing WCSAXES crash read_wcs_from_header()

1

I get the following error when reading a file with a WCS that doesn't have the WCSAXES keyword: {{{ /Users/parejkoj/lsst/lsstsw/miniconda/lib/python2.7/site-packages/gwcs/utils.pyc in read_wcs_from_header(header) 97 keys = ctypes.keys() 98 for key in...

Getting some more information out of the Stats module might help debug problems when loading stats data.

I found the PR #140 that added the interactive login kwarg to `connect()`, but without finding that PR, I wouldn't have known about it. I added a docstring for the...

Just reporting the maximum absolute difference does not tell you where np.allclose() was failing, because it uses a relative+absolute comparison.

Specify that __all__ should be a tuple

6

We've had some conversation about this on slack in the past, and settled on tuple, but never specified it in the dev guide.