Description
Bug summary
Originally reported in the thread of #8431.
When using hatches with a patch and exporting to a PDF, the patch face color seems to also be applied to (or to overlay) the hatches when viewing the file with Acrobat Reader, which is neither the case in the Matplotlib interactive window nor when opening the same PDF with Evince. Not sure if it is the alpha value of the face color that is wrongly interpreted, or simply the z-order between the face color and the hatches.
Code for reproduction
import matplotlib.pyplot as plt
import matplotlib.patches as mpatches
import matplotlib as mpl
rect = mpatches.Rectangle((0.25, 0.25), 0.5, 0.5, hatch="x",
edgecolor="darkred", facecolor=[0.5, 0.5, 0.5, 0.1])
fig, ax = plt.subplots()
ax.add_patch(rect)
fig.savefig("with_{0}.pdf".format(mpl.__version__))Actual outcome
An exemple of the PDF produced by the snippet above:
with_2.1.0.post933+gd046efbc2.pdf
A screenshot comparing this file opened with Evince (on the left) and with Acrobat Reader (on the right):
I get a similar output/behavior with Matplotlib 2.0.0. However, with Matplotlib 1.5.3, something is going wrong and I am thrown the following traceback below, so I do not know if it is really a kind of regression.
# Traceback when tryin to run the MWE with tags/v1.5.3
---------------------------------------------------------------------------
ImportError Traceback (most recent call last)
~/Playground/Matplotlib/transparent_hatches/mwe_issue.py in <module>()
10 fig, ax = plt.subplots()
11 ax.add_patch(rect)
---> 12 fig.savefig("with_{0}.pdf".format(mpl.__version__))
~/FOSS/matplotlib/lib/matplotlib/figure.py in savefig(self, *args, **kwargs)
1561 self.set_frameon(frameon)
1562
-> 1563 self.canvas.print_figure(*args, **kwargs)
1564
1565 if frameon:
~/FOSS/matplotlib/lib/matplotlib/backends/backend_qt5agg.py in print_figure(self, *args, **kwargs)
201
202 def print_figure(self, *args, **kwargs):
--> 203 FigureCanvasAgg.print_figure(self, *args, **kwargs)
204 self.draw()
205
~/FOSS/matplotlib/lib/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, **kwargs)
2137
2138 # get canvas object and print method for format
-> 2139 canvas = self._get_output_canvas(format)
2140 print_method = getattr(canvas, 'print_%s' % format)
2141
~/FOSS/matplotlib/lib/matplotlib/backend_bases.py in _get_output_canvas(self, format)
2069
2070 # check if there is a default canvas for the requested format
-> 2071 canvas_class = get_registered_canvas_class(format)
2072 if canvas_class:
2073 return self.switch_backends(canvas_class)
~/FOSS/matplotlib/lib/matplotlib/backend_bases.py in get_registered_canvas_class(format)
135 backend_class = _default_backends[format]
136 if cbook.is_string_like(backend_class):
--> 137 backend_class = import_module(backend_class).FigureCanvas
138 _default_backends[format] = backend_class
139 return backend_class
~/anaconda3/envs/matplotlib_dev/lib/python3.6/importlib/__init__.py in import_module(name, package)
124 break
125 level += 1
--> 126 return _bootstrap._gcd_import(name[level:], package, level)
127
128
~/anaconda3/envs/matplotlib_dev/lib/python3.6/importlib/_bootstrap.py in _gcd_import(name, package, level)
~/anaconda3/envs/matplotlib_dev/lib/python3.6/importlib/_bootstrap.py in _find_and_load(name, import_)
~/anaconda3/envs/matplotlib_dev/lib/python3.6/importlib/_bootstrap.py in _find_and_load_unlocked(name, import_)
~/anaconda3/envs/matplotlib_dev/lib/python3.6/importlib/_bootstrap.py in _load_unlocked(spec)
~/anaconda3/envs/matplotlib_dev/lib/python3.6/importlib/_bootstrap_external.py in exec_module(self, module)
~/anaconda3/envs/matplotlib_dev/lib/python3.6/importlib/_bootstrap.py in _call_with_frames_removed(f, *args, **kwds)
~/FOSS/matplotlib/lib/matplotlib/backends/backend_pdf.py in <module>()
32 from matplotlib.backend_bases import RendererBase, GraphicsContextBase,\
33 FigureManagerBase, FigureCanvasBase
---> 34 from matplotlib.backends.backend_mixed import MixedModeRenderer
35 from matplotlib.cbook import Bunch, is_string_like, \
36 get_realpath_and_stat, is_writable_file_like, maxdict
~/FOSS/matplotlib/lib/matplotlib/backends/backend_mixed.py in <module>()
4 from matplotlib.externals import six
5
----> 6 from matplotlib._image import frombuffer
7 from matplotlib.backends.backend_agg import RendererAgg
8 from matplotlib.tight_bbox import process_figure_for_rasterizing
ImportError: cannot import name 'frombuffer'
Expected outcome
The same behavior with both PDF viewers, i.e. the hatches not being affected by the the face color of the patch.
Matplotlib version
- Operating system: Linux (Fedora 27)
- Matplotlib version: 1.5.3, 2.0.0 and master
- Matplotlib backend (
print(matplotlib.get_backend())): - Python version: 3.6, from conda
- Jupyter version (if applicable):
- Other softwares: Acrobat Reader 9.5.5