code: def psffunc(self, x, y, z, **kwargs):
          
          #do_pinhole?? FIXME
          if self.polychromatic:
              func = psfcalc.calculate_polychrome_pinhole_psf
          else:
              func = psfcalc.calculate_pinhole_psf
          x0, y0 = [psfcalc.vec_to_halfvec(v) for v in [x,y]]
          vls = psfcalc.wrap_and_calc_psf(x0, y0, z, func, **kwargs)
          return vls / vls.sum()
docs: Calculates a pinhole psf