[AstroPy] PyGuide 2.0 released

[Russell E Owen]

PyGuide 2.0 is now available from 
<http://www.astro.washington.edu/rowen/PyGuide%20Manual.html>.

PyGuide offers image analysis routines for telescope guiding, 
including a star finder, centroider and star shape fitter. The 
algorithms are designed to work well with partial images, e.g. where 
much of the image of a star is lost down a spectrograph slit or off 
the edge of a coherent fiber optic bundle.

Version 2.0 is a major overhaul based on use at Apache Point 
Observatory. In particular, centroid and starShape have been much 
improved.

StarShape still does not measure ellipticity. If anyone has a 
reliable algorithm for measuring ellipticity even on heavily masked 
data, I would like to know about it. By reliable I mean that it 
includes an error estimate so I know when not to trust the results.

-- Russell

P.S. Future plans:
- Add a measure of ellipticity
- Replace satLevel with a saturation mask
- Work with Float32 images instead of UInt16
the last two changes will make PyGuide easier to use with flat-fielded images.