def compute_principle_points(self, seq):
""" Returns paraxial p and q rays, plus partial first order data.
Args:
seq: a sequence containing interfaces and gaps to be traced.
for each iteration, the sequence should return a
list containing: **Intfc, Gap, Trfm, Index, Z_Dir**
Returns:
(p_ray, q_ray, (efl, pp1, ppk, ffl, bfl))
- p_ray: [ht, slp, aoi], [1, 0, -]
- q_ray: [ht, slp, aoi], [0, 1, -]
- efl: effective focal length
- pp1: distance of front principle plane from 1st interface
- ppk: distance of rear principle plane from last interface
- ffl: front focal length
- bfl: back focal length
"""
n_0 = seq[0][mc.Indx]
z_dir_before = seq[0][mc.Zdir]
n_k = seq[-1][mc.Indx]
z_dir_k = seq[-1][mc.Zdir]
path = [[Surface(), Gap(), None, n_0, z_dir_before]]
path.extend(seq[1:])
pp_info = fo.compute_principle_points(iter(path),
n_0=z_dir_before * n_0,
n_k=z_dir_k * n_k)
return pp_info
def compute_principle_points(self, node, seq):
n_0 = seq[0][mc.Indx]
z_dir_before = seq[0][mc.Zdir]
n_k = seq[-1][mc.Indx]
z_dir_k = seq[-1][mc.Zdir]
path = [[Surface(), Gap(), None, n_0, z_dir_before]]
path.extend(seq[1:])
pp_info = fo.compute_principle_points(iter(path),
n_0=z_dir_before * n_0,
n_k=z_dir_k * n_k)
return pp_info