File: //usr/lib/python2.7/dist-packages/matplotlib/tests/test_agg.py
from __future__ import (absolute_import, division, print_function,
unicode_literals)
from matplotlib.externals import six
import io
import os
import numpy as np
from numpy.testing import assert_array_almost_equal
from matplotlib.image import imread
from matplotlib.backends.backend_agg import FigureCanvasAgg as FigureCanvas
from matplotlib.figure import Figure
from matplotlib.testing.decorators import cleanup
from matplotlib import pyplot as plt
from matplotlib import collections
from matplotlib import path
@cleanup
def test_repeated_save_with_alpha():
# We want an image which has a background color of bluish green, with an
# alpha of 0.25.
fig = Figure([1, 0.4])
canvas = FigureCanvas(fig)
fig.set_facecolor((0, 1, 0.4))
fig.patch.set_alpha(0.25)
# The target color is fig.patch.get_facecolor()
buf = io.BytesIO()
fig.savefig(buf,
facecolor=fig.get_facecolor(),
edgecolor='none')
# Save the figure again to check that the
# colors don't bleed from the previous renderer.
buf.seek(0)
fig.savefig(buf,
facecolor=fig.get_facecolor(),
edgecolor='none')
# Check the first pixel has the desired color & alpha
# (approx: 0, 1.0, 0.4, 0.25)
buf.seek(0)
assert_array_almost_equal(tuple(imread(buf)[0, 0]),
(0.0, 1.0, 0.4, 0.250),
decimal=3)
@cleanup
def test_large_single_path_collection():
buff = io.BytesIO()
# Generates a too-large single path in a path collection that
# would cause a segfault if the draw_markers optimization is
# applied.
f, ax = plt.subplots()
collection = collections.PathCollection(
[path.Path([[-10, 5], [10, 5], [10, -5], [-10, -5], [-10, 5]])])
ax.add_artist(collection)
ax.set_xlim(10**-3, 1)
plt.savefig(buff)
def report_memory(i):
pid = os.getpid()
a2 = os.popen('ps -p %d -o rss,sz' % pid).readlines()
print(i, ' ', a2[1], end=' ')
return int(a2[1].split()[0])
# This test is disabled -- it uses old API. -ADS 2009-09-07
## def test_memleak():
## """Test agg backend for memory leaks."""
## from matplotlib.ft2font import FT2Font
## from numpy.random import rand
## from matplotlib.backend_bases import GraphicsContextBase
## from matplotlib.backends._backend_agg import RendererAgg
## fontname = '/usr/local/share/matplotlib/Vera.ttf'
## N = 200
## for i in range( N ):
## gc = GraphicsContextBase()
## gc.set_clip_rectangle( [20, 20, 20, 20] )
## o = RendererAgg( 400, 400, 72 )
## for j in range( 50 ):
## xs = [ 400*int(rand()) for k in range(8) ]
## ys = [ 400*int(rand()) for k in range(8) ]
## rgb = (1, 0, 0)
## pnts = zip( xs, ys )
## o.draw_polygon( gc, rgb, pnts )
## o.draw_polygon( gc, None, pnts )
## for j in range( 50 ):
## x = [ 400*int(rand()) for k in range(4) ]
## y = [ 400*int(rand()) for k in range(4) ]
## o.draw_lines( gc, x, y )
## for j in range( 50 ):
## args = [ 400*int(rand()) for k in range(4) ]
## rgb = (1, 0, 0)
## o.draw_rectangle( gc, rgb, *args )
## if 1: # add text
## font = FT2Font( fontname )
## font.clear()
## font.set_text( 'hi mom', 60 )
## font.set_size( 12, 72 )
## o.draw_text_image( font.get_image(), 30, 40, gc )
## fname = "agg_memleak_%05d.png"
## o.write_png( fname % i )
## val = report_memory( i )
## if i==1: start = val
## end = val
## avgMem = (end - start) / float(N)
## print 'Average memory consumed per loop: %1.4f\n' % (avgMem)
## #TODO: Verify the expected mem usage and approximate tolerance that
## # should be used
## #self.checkClose( 0.32, avgMem, absTol = 0.1 )
## # w/o text and w/o write_png: Average memory consumed per loop: 0.02
## # w/o text and w/ write_png : Average memory consumed per loop: 0.3400
## # w/ text and w/ write_png : Average memory consumed per loop: 0.32
@cleanup
def test_marker_with_nan():
# This creates a marker with nans in it, which was segfaulting the
# Agg backend (see #3722)
fig, ax = plt.subplots(1)
steps = 1000
data = np.arange(steps)
ax.semilogx(data)
ax.fill_between(data, data*0.8, data*1.2)
buf = io.BytesIO()
fig.savefig(buf, format='png')
@cleanup
def test_long_path():
buff = io.BytesIO()
fig, ax = plt.subplots()
np.random.seed(0)
points = np.random.rand(70000)
ax.plot(points)
fig.savefig(buff, format='png')
if __name__ == "__main__":
import nose
nose.runmodule(argv=['-s', '--with-doctest'], exit=False)