def gaus_curv(arr):
arr_x = cderivative(arr, 'X_DIR', 1)
arr_y = cderivative(arr, 'Y_DIR', 1)
rarr_x = irfft2(arr_x)
rarr_y = irfft2(arr_y)
denom = (rarr_x**2 + rarr_y**2 + 1)**2
rarr_xx = irfft2(cderivative(arr_x, 'X_DIR', 1))
rarr_yy = irfft2(cderivative(arr_y, 'Y_DIR', 1))
rarr_xy = irfft2(cderivative(arr_x, 'Y_DIR', 1))
return (rarr_xx * rarr_yy - rarr_xy**2) / denom
def mean_curv(arr):
arr_x = cderivative(arr, 'X_DIR', 1)
arr_y = cderivative(arr, 'Y_DIR', 1)
rarr_x = irfft2(arr_x)
rarr_y = irfft2(arr_y)
denom = np.power(rarr_x**2 + rarr_y**2 + 1, 1.5)
rarr_xx = irfft2(cderivative(arr_x, 'X_DIR', 1))
rarr_yy = irfft2(cderivative(arr_y, 'Y_DIR', 1))
rarr_xy = irfft2(cderivative(arr_x, 'Y_DIR', 1))
term1 = (1 + rarr_x**2) * rarr_yy
term2 = (1 + rarr_y**2) * rarr_xx
term3 = -2.0 * rarr_x * rarr_y * rarr_xy
return 0.5 * (term1 + term2 + term3) / denom
