Created
March 23, 2016 06:23
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# -*- coding: utf-8 -*- | |
from __future__ import absolute_import | |
from __future__ import division | |
from __future__ import print_function | |
from __future__ import unicode_literals | |
import numpy as np | |
import abel | |
import matplotlib.pyplot as plt | |
gauss = lambda r, r0, sigma: np.exp(-(r-r0)**2/sigma**2) | |
sigma = 10 | |
# 2D Gaussian ----------- | |
# pixel coordinates | |
n = 200 | |
rows, cols = n, n | |
r2 = rows//2 | |
c2 = cols//2 | |
x = np.linspace(-c2+0.5, c2-0.5, cols) | |
y = np.linspace(-r2+0.5, r2-0.5, rows) | |
X, Y = np.meshgrid(x, y) | |
IM = gauss(X, 0, sigma) # cylinderical Gaussian max located at pixel=0 | |
# @DanHickstein see #155 | |
Q0, Q1, Q2, Q3 = abel.tools.symmetry.get_image_quadrants(IM) | |
qspeed = abel.tools.vmi.angular_integration(Q0, origin=(0, 0)) | |
# Abel transform | |
AQ0 = abel.onion_peeling.onion_peeling_transform(Q0, shift_grid=False) | |
ospeed = abel.tools.vmi.angular_integration(AQ0, origin=(0, 0)) | |
plt.subplot(221) | |
plt.plot(*qspeed, label="orig.") | |
plt.plot(ospeed[0], ospeed[1]*qspeed[1][2]/ospeed[1][2], label="onion") | |
plt.legend() | |
plt.title("n=100", fontsize=10) | |
plt.axis(xmax=49) | |
n = 201 | |
rows, cols = n, n | |
r2 = rows//2 | |
c2 = cols//2 | |
x = np.linspace(-c2, c2, cols) | |
y = np.linspace(-r2, r2, rows) | |
X, Y = np.meshgrid(x, y) | |
IM = gauss(X, 0, sigma) # cylinderical Gaussian max located at pixel=0 | |
# @DanHickstein see #155 | |
#Q0 = IM[:r2, c2:] # quadrant, top-right | |
Q0, Q1, Q2, Q3 = abel.tools.symmetry.get_image_quadrants(IM) | |
Q0_copy = Q0.copy() | |
qspeed = abel.tools.vmi.angular_integration(Q0, origin=(0, 0)) | |
# Plots | |
plt.suptitle("inverse Abel transforms 2D-Gaussian cylinder $\sigma={:g}$".format(sigma)) | |
Q0 = Q0_copy | |
AQ0 = abel.hansenlaw.hansenlaw_transform(Q0) | |
hspeed = abel.tools.vmi.angular_integration(AQ0, origin=(0, 0)) | |
plt.subplot(222) | |
plt.plot(*qspeed, label="orig.") | |
plt.plot(hspeed[0], hspeed[1]*qspeed[1][2]/hspeed[1][2], label="hansenlaw") | |
plt.legend() | |
plt.title("n=101", fontsize=10) | |
plt.axis(xmax=49) | |
Q0 = Q0_copy | |
AQ0 = abel.basex.basex_transform(Q0) | |
bspeed = abel.tools.vmi.angular_integration(AQ0, origin=(0, 0)) | |
plt.subplot(223) | |
plt.plot(*qspeed, label="orig.") | |
plt.plot(bspeed[0], bspeed[1]*qspeed[1][2]/bspeed[1][2], label="basex") | |
plt.legend() | |
plt.legend() | |
plt.title("n=101", fontsize=10) | |
plt.axis(xmax=49) | |
Q0 = Q0_copy | |
AQ0 = abel.three_point.three_point_transform(Q0) | |
tspeed = abel.tools.vmi.angular_integration(AQ0, origin=(0, 0)) | |
plt.subplot(224) | |
plt.plot(*qspeed, label="orig.") | |
plt.plot(tspeed[0], tspeed[1]*qspeed[1][2]/tspeed[1][2], label="three_point") | |
plt.legend() | |
plt.title("n=101", fontsize=10) | |
plt.axis(xmax=49) | |
plt.savefig("cf_2d.png", dpi=100) | |
plt.show() |
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