> In galsim/base.py:
> 
> > @@ -310,6 +310,29 @@ def applyShear(self, *args, **kwargs):
> >          self.SBProfile.applyShear(shear._shear)
> >          self.__class__ = GSObject
> >  
> > +    def applyLensing(self, g1, g2, mu):
> I didn't see any unit tests that check this new function. It should be sufficient to just check that obj.applyLensing(g1,g2,mu) draws the same image as obj.applyShear(g1,g2); obj.applyMagnification(sqrt(mu)).
> 
You're right, I forgot.  Will add tomorrow.

> Which raises the question: Should we regularize the sqrt? The applyMagnification function assumes a linear scale to match applyDilation (for which I think the linear factor is intuitive). Should we change this to accept a "mu" value rather than a "scale" value to match the more lensing-typical meaning?
> 

Hmmm, right.  I think that applyMagnification should be changed in this way.  Will do that when I make the applyLensing unit tests.