def _computeChebyshevDerivative(self, star):
"""Return the derivatives w.r.t. the Chebyshev components."""
cx = (self.bbox.getMinX() + self.bbox.getMaxX())/2.0
cy = (self.bbox.getMinY() + self.bbox.getMaxY())/2.0
sx = 2.0 / self.bbox.getWidth()
sy = 2.0 / self.bbox.getHeight()
Tx = np.array([CHEBYSHEV_T[i](sx*(star.getXFocal() - cx))
for i in range(self.order+1)], dtype=float)
Ty = np.array([CHEBYSHEV_T[i](sy*(star.getYFocal() - cy))
for i in range(self.order+1)], dtype=float)
expect = []
for j in range(len(Ty)):
for i in range(0, self.order-j+1):
expect.append(Ty[j]*Tx[i])
return np.array(expect)
def _computeChipDerivative(self, star):
return self.value * self._evaluate_chebyshev(star.getXFocal(),
star.getYFocal())
def _computeChipDerivative(self, star):
return self.value * self._evaluate_chebyshev(star.getXFocal(), star.getYFocal())