Commit c54b8571 authored by Daniel Brown's avatar Daniel Brown
Browse files

adding in new integrator for knm using higher order newton-cotes methods and...

adding in new integrator for knm using higher order newton-cotes methods and analytic solution for square aperture
parent bd9f9d8c
import pykat
import numpy as np
from pykat.optics.knm import square_aperture_HG_knm, riemann_HG_knm
import math
R = 0.15
q = pykat.beam_param(w0=6e-3, z=2000)
N = 1201
mode_i = (0,0)
mode_o = (0,0)
k = square_aperture_HG_knm(mode_i, mode_o, q, R)
x = y = np.linspace(-R, R, N)
Axy = np.ones((N,N))
k_ = riemann_HG_knm(x, y, mode_i, mode_o, q, q, Axy=Axy, newtonCotesOrder=2)
print "%15.15f + %15.15fi" % (k.real, k.imag)
print "%15.15f + %15.15fi" % (k_.real, k_.imag), abs(k-k_)/1e-6, "ppm"
\ No newline at end of file
......@@ -318,7 +318,15 @@ class HG_beam(object):
self._qy = copy.deepcopy(value)
else:
self._qy = beam_param(q=complex(value))
@property
def constant_x(self):
return self.__xpre_const
@property
def constant_y(self):
return self.__ypre_const
def _calc_constants(self):
self.__xpre_const = math.pow(2.0/math.pi, 0.25)
self.__xpre_const *= np.sqrt(1.0/(self._qx.w0 * 2**(self._n) * np.math.factorial(self._n)))
......@@ -338,7 +346,7 @@ class HG_beam(object):
self.__invqx = 1/ self._qx.q
self.__invqy = 1/ self._qy.q
def Un(self, x):
return self.__xpre_const * self._hn(self.__sqrt2_wxz * x) * np.exp(-0.5j * self.__kx * x*x * self.__invqx)
......
......@@ -6,6 +6,10 @@ from pykat.external.progressbar import ProgressBar, ETA, Percentage, Bar
from scipy.interpolate import interp2d
from scipy.integrate import dblquad
from pykat.optics.romhom import ROMWeights
from math import factorial
from pykat.maths.hermite import hermite
from scipy.misc import comb
from scipy.integrate import newton_cotes
import time
import pykat.optics.maps
......@@ -144,15 +148,16 @@ def adaptive_knm(mode_in, mode_out, q1, q2, q1y=None, q2y=None, smap=None, delta
return R + 1j * I
def riemann_HG_knm(x, y, mode_in, mode_out, q1, q2, q1y=None, q2y=None, Axy=None, cache=None, delta=(0,0), params={}):
def riemann_HG_knm(x, y, mode_in, mode_out, q1, q2, q1y=None, q2y=None,
Axy=None, cache=None, delta=(0,0), params={}, newtonCotesOrder=0):
if Axy == None:
if Axy is None:
Axy == np.ones((len(x), len(y)))
if q1y == None:
if q1y is None:
q1y = q1
if q2y == None:
if q2y is None:
q2y = q2
if len(mode_in) != 2 or len(mode_out) != 2:
......@@ -164,11 +169,35 @@ def riemann_HG_knm(x, y, mode_in, mode_out, q1, q2, q1y=None, q2y=None, Axy=None
if cache == None:
Hg_in = HG_beam(qx=q1, qy=q1y, n=mode_in[0], m=mode_in[1])
Hg_out = HG_beam(qx=q2, qy=q2y, n=mode_out[0], m=mode_out[1])
U1 = Hg_in.Unm(x+delta[0], y+delta[1])
U2 = Hg_out.Unm(x,y).conjugate()
return dx * dy * np.einsum('ij,ij', Axy, U1*U2)
if newtonCotesOrder > 0:
W = newton_cotes(newtonCotesOrder, 1)[0]
if newtonCotesOrder > 1:
if (len(x) - len(W)) % newtonCotesOrder != 0:
raise ValueError("To use Newton-Cotes order {0} the number of data points in x must ensure: (N_x - ({0}+1)) mod {0} == 0".format(newtonCotesOrder) )
if (len(y) - len(W)) % newtonCotesOrder != 0:
raise ValueError("To use Newton-Cotes order {0} the number of data points in y must ensure: (N_y - ({0}+1)) mod {0} == 0".format(newtonCotesOrder) )
wx = np.zeros(x.shape, dtype=np.float64)
wy = np.zeros(y.shape, dtype=np.float64)
N = len(W)
for i in range(0, (len(wx)-1)/newtonCotesOrder): wx[(i*(N-1)):(i*(N-1)+N)] += W
for i in range(0, (len(wy)-1)/newtonCotesOrder): wy[(i*(N-1)):(i*(N-1)+N)] += W
Wxy = np.outer(wx, wy)
if newtonCotesOrder == 0:
return dx * dy * np.einsum('ij,ij', Axy, U1*U2)
else:
return dx * dy * np.einsum('ij,ij', Axy, U1*U2*Wxy)
else:
strx = "u1[%i,%i]" % (mode_in[0], mode_out[0])
......@@ -438,6 +467,63 @@ def bayerhelms_HG_knm(mode_in, mode_out, q1, q2, q1y=None, q2y=None, gamma=(0,0)
return __bayerhelms_kn(n,_n, q1, q2, 2*gamma[0]) * __bayerhelms_kn(m, _m, q1y, q2y, 2*gamma[1])
def __sqaure_knm_int(n, _n, R):
# This uses the H_n(x) * H_m(x) product identity to reduce the overlap into
# a sum of factorial and an integral of a single Hermite with a gaussian function
# thus making it easier to solve
expR = math.exp(-(R**2))
S = 0
for j in range(0, min(n, _n)+1):
_j1 = _n + n - 2*j - 1
if _j1+1 == 0:
# for the zeroth order we just have the gaussian integral to solve
L = math.sqrt(math.pi) * math.erf(R)
elif (_j1+1) % 2 == 1:
# if the Hermite is odd then the integral is always 0 as its anti-symmetric
L = 0
else:
L = 2 * hermite(_j1, 0) - expR * (hermite(_j1, R) - hermite(_j1, -R))
I = 2**j * factorial(j) * comb(n, j) * comb(_n, j)
S += I * L
return S
def square_aperture_HG_knm(mode_in, mode_out, q, R):
"""
Computes the coupling coefficients for a square aperture.
"""
# x modes
n = mode_in[0]
_n = mode_out[0]
# y modes
m = mode_in[1]
_m = mode_out[1]
hg1 = HG_beam(q, n=n, m=m)
hg2 = HG_beam(q, n=_n, m=_m)
kx = hg1.constant_x * hg2.constant_x.conjugate()
ky = hg1.constant_y * hg2.constant_y.conjugate()
print hg1.constant_x, hg2.constant_x, hg1.constant_y, hg2.constant_y
f = q.w / math.sqrt(2)
R = R / (q.w / math.sqrt(2))
kx *= f
kx *= __sqaure_knm_int(n, _n, R)
ky *= f
ky *= __sqaure_knm_int(m, _m, R)
return kx * ky
def knmHG(couplings, q1, q2, surface_map=None, q1y=None, q2y=None, method="riemann", verbose=False, profile=False, gamma=(0,0), delta=(0,0), params={}):
......@@ -547,6 +633,9 @@ def knmHG(couplings, q1, q2, surface_map=None, q1y=None, q2y=None, method="riema
return K.reshape(couplings.shape[:-1])
def plot_knm_matrix(couplings, knm):
import pylab as plt
......
......@@ -177,7 +177,11 @@ def makeReducedBasis(x, isModeMatched=True, tolerance = 1e-12, sigma = 1, greedy
greedyfile = os.path.join(pykat.__path__[0],'optics','greedypoints',greedypts)
limits = np.loadtxt(greedyfile, usecols=(1,))[:5]
# Two potential different formats
try:
limits = np.loadtxt(greedyfile, usecols=(3,))[:5]
except IndexError:
limits = np.loadtxt(greedyfile, usecols=(1,))[:5]
romlimits = ROMLimits(w0min=limits[0], w0max=limits[1], zmin=limits[2], zmax=limits[3], max_order=limits[4])
......
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