Mixin base class for fitting shapelet approximations to the PSF model
This class does almost all of the work for its two derived classes,
GeneralShapeletPsfApproxSingleFramePlugin and
GeneralShapeletPsfApproxForcedPlugin, which simply adapt it to the
slightly different interfaces for single-frame and forced measurement. It
in turn delegates its work to the C++ GeneralPsfFitter class; it holds
sequence of these corresponding to different models (generally with
increasing complexity). Each GeneralPsfFitter starts with the result of
the previous one as an input, using GeneralPsfFitter::adapt to hopefully
allow these previous fits to reduce the time spent on the next one.
At present, this plugin does not define any failure flags, which will
almost certainly have to be changed in the future. So far, however, I
haven't actually seen it fail on any PSFs I've given it, so I'll wait
until we can run on large enough data volumes to see what the actual
failure modes are, instead of trying to guess them in advance.
Definition at line 109 of file psfContinued.py.