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#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (C) 2011, 2012 Povilas Kanapickas <povilas@radix.lt>
#
# This file is part of cppreference-doc
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see http://www.gnu.org/licenses/.
import matplotlib.cm as cm
import matplotlib.colors as colors
import matplotlib.pyplot as plt
import os
import numpy as np
import math
import pprint
font = {'family' : 'DejaVu Sans',
'weight' : 'normal',
'size' : 18}
plt.rc('font', **font)
plt.rc('contour', **{ 'negative_linestyle' : 'solid'})
# generate data
X = np.arange(-1, 1.05, 0.02)
Y = np.arange(-1, 1.05, 0.02)
X, Y = np.meshgrid(X, Y)
Z = np.arctan2(Y,X)
# generate labels
levels = [-math.pi*3/4, -math.pi*2/4, -math.pi/4,
0, math.pi/4, math.pi/2, math.pi*3/4 ]
labels = [u'-3/4 π', u'-1/2 π', u'-1/4 π', '0', u'1/4 π', u'1/2 π', u'3/4 π' ]
fmt = {}
for l,s in zip( levels, labels ):
fmt[l] = s
# generate plot
fig = plt.figure(figsize=(475.0/72.0,400.0/72.0))
ax = fig.add_subplot(111)
ct = ax.contour(X, Y, Z, levels=levels, linewidths=0.5, colors='k')
ax.clabel(ct, fmt=fmt, colors = '#000000', fontsize=14)
# HACK - remove the contour label at discontinuity of atan2
ct.labelTexts[5].set_text('')
pc = ax.pcolor(X, Y, Z, cmap=plt.get_cmap("Spectral_r"), vmin=-3.2, vmax=3.2)
fig.colorbar(pc)
ax.set_xlim((-1.0, 1.0))
ax.set_ylim((-1.0, 1.0))
ax.set_axisbelow(True)
ax.tick_params(pad = 15)
ax.set_aspect(1.0)
fig.savefig('output/math-atan2.png')
plt.close()
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