On Feb 7, 2013, at 6:41 AM, Barnaby Rowe <notifications@github.com> wrote:

> In galsim/base.py:
> 
> > @@ -1384,15 +1391,45 @@ class InterpolatedImage(GSObject):
> >      choose interpolants and pad factors, and no warnings are raised when the code is modified to
> >      choose some combination that is known to give significant error.
> >  
> > +    The user can choose to have the image padding use zero (default), Gaussian random noise of some
> > +    variance, or a Gaussian but correlated noise field that is specified either as an ImageCorrFunc,
> > +    an Image (from which a noise correlation function is derived), or a string (interpreted as a
> > +    filename containing an image to use for deriving the noise correlation function).  The user can
> > +    also pass in a random number generator to be used for noise generation.
> I discovered that most of the time for the nopadding case is in the Quintic interpolant setup.
> 
> Mike, I'm now worried that the ._rootps_store cache in the ImageCorrFunc isn't being properly used in these tests when the cf is passed to the InterpolatedImage, otherwise it shouldn't be necessary (as far as I can see) to spend much time in Quintic at all when using the applyNoiseTo method.
> 
In the no-padding case, the ImageCorrFunc isn't used at all.  I thought Mike meant the problem was in the Quintic used as the k-space interpolant for the InterpolatedImage itself…?