You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
88 lines
2.2 KiB
Python
88 lines
2.2 KiB
Python
"""
|
|
Basic FDTD field updates
|
|
"""
|
|
from typing import List, Callable, Tuple, Dict
|
|
import numpy
|
|
|
|
from .. import dx_lists_t, field_t, field_updater
|
|
|
|
__author__ = 'Jan Petykiewicz'
|
|
|
|
|
|
def curl_h(dxes: dx_lists_t = None) -> field_updater:
|
|
"""
|
|
Curl operator for use with the H field.
|
|
|
|
:param dxes: Grid parameters [dx_e, dx_h] as described in meanas.types
|
|
:return: Function for taking the discretized curl of the H-field, F(H) -> curlH
|
|
"""
|
|
if dxes:
|
|
dxyz_b = numpy.meshgrid(*dxes[1], indexing='ij')
|
|
|
|
def dh(f, ax):
|
|
return (f - numpy.roll(f, 1, axis=ax)) / dxyz_b[ax]
|
|
else:
|
|
def dh(f, ax):
|
|
return f - numpy.roll(f, 1, axis=ax)
|
|
|
|
def ch_fun(h: field_t) -> field_t:
|
|
output = numpy.empty_like(h)
|
|
output[0] = dh(h[2], 1)
|
|
output[1] = dh(h[0], 2)
|
|
output[2] = dh(h[1], 0)
|
|
output[0] -= dh(h[1], 2)
|
|
output[1] -= dh(h[2], 0)
|
|
output[2] -= dh(h[0], 1)
|
|
return output
|
|
|
|
return ch_fun
|
|
|
|
|
|
def curl_e(dxes: dx_lists_t = None) -> field_updater:
|
|
"""
|
|
Curl operator for use with the E field.
|
|
|
|
:param dxes: Grid parameters [dx_e, dx_h] as described in meanas.types
|
|
:return: Function for taking the discretized curl of the E-field, F(E) -> curlE
|
|
"""
|
|
if dxes is not None:
|
|
dxyz_a = numpy.meshgrid(*dxes[0], indexing='ij')
|
|
|
|
def de(f, ax):
|
|
return (numpy.roll(f, -1, axis=ax) - f) / dxyz_a[ax]
|
|
else:
|
|
def de(f, ax):
|
|
return numpy.roll(f, -1, axis=ax) - f
|
|
|
|
def ce_fun(e: field_t) -> field_t:
|
|
output = numpy.empty_like(e)
|
|
output[0] = de(e[2], 1)
|
|
output[1] = de(e[0], 2)
|
|
output[2] = de(e[1], 0)
|
|
output[0] -= de(e[1], 2)
|
|
output[1] -= de(e[2], 0)
|
|
output[2] -= de(e[0], 1)
|
|
return output
|
|
|
|
return ce_fun
|
|
|
|
|
|
def maxwell_e(dt: float, dxes: dx_lists_t = None) -> field_updater:
|
|
curl_h_fun = curl_h(dxes)
|
|
|
|
def me_fun(e: field_t, h: field_t, epsilon: field_t):
|
|
e += dt * curl_h_fun(h) / epsilon
|
|
return e
|
|
|
|
return me_fun
|
|
|
|
|
|
def maxwell_h(dt: float, dxes: dx_lists_t = None) -> field_updater:
|
|
curl_e_fun = curl_e(dxes)
|
|
|
|
def mh_fun(e: field_t, h: field_t):
|
|
h -= dt * curl_e_fun(e)
|
|
return h
|
|
|
|
return mh_fun
|