René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"'QPixmap' object has no attribute 'setDevicePixelRatio'","articleBody":"\r\n**Report**\r\n\r\n**Summary**\r\nI was trying to use networkx to draw some graphs but matplotlib fails. So I tested some actual matplotlib examples without including networkx related code and I reproduced the same error. I suspect it may be related to Qt but cannot be sure. The error states as:\r\n\r\n\u003e AttributeError: 'QPixmap' object has no attribute 'setDevicePixelRatio'\r\n\r\n**Code for reproduction**\r\n\r\nI am using python 2.7. The code I used was:\r\n\r\n```\r\nimport numpy as np\r\nimport matplotlib.pyplot as plt\r\n\r\nX = np.linspace(-np.pi, np.pi, 256, endpoint=True)\r\nC,S = np.cos(X), np.sin(X)\r\n\r\nplt.plot(X,C)\r\nplt.plot(X,S)\r\n\r\nplt.show()\r\n```\r\n\r\nbut it already fails in this line:\r\n\r\n`plt.plot(X,C)`\r\n\r\n\r\n**Expected outcome**\r\nExpected outcome is this picture: \r\n\r\n![picture](https://www.labri.fr/perso/nrougier/teaching/matplotlib/figures/exercice_1.png)\r\n\r\n**Matplotlib version**\r\n  * Operating System: Lubuntu, 14.04.5 LTS\r\n  * Matplotlib Version: 2.0.1\r\n  * Python Version: Python 2.7.6\r\n\r\nQmake:\r\n\u003e qmake --version\r\nQMake version 3.0\r\nUsing Qt version 5.2.1 in /usr/lib/x86_64-linux-gnu\r\n\r\nSystem info:\r\n\u003eDistributor ID: Ubuntu\r\nDescription: Ubuntu 14.04.5 LTS\r\nRelease:\t14.04\r\nCodename: trusty\r\n\r\n\u003euname -a\r\nLinux thesisvm 4.4.0-75-generic #96~14.04.1-Ubuntu SMP Thu Apr 20 11:06:30 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux\r\n\r\nMatplotlib info:\r\n\r\n\u003e matplotlib.__version__\r\n'2.0.1'\r\n\u003ematplotlib.__file__\r\n'/usr/local/lib/python2.7/dist-packages/matplotlib/__init__.pyc'\r\n\r\nI cannot reproduce all the commands I issued but can give an outline. \r\nI issued these commands:\r\n\r\n`sudo apt-get build-dep python-matplotlib`\r\n`sudo pip install matplotlib`\r\n\r\n\r\nFull error trace:\r\n\r\n\u003e plt.plot(X,C)\r\nTraceback (most recent call last):\r\n  File \"\u003cstdin\u003e\", line 1, in \u003cmodule\u003e\r\n  File \"/usr/local/lib/python2.7/dist-packages/matplotlib/pyplot.py\", line 3306, in plot\r\n    ax = gca()\r\n  File \"/usr/local/lib/python2.7/dist-packages/matplotlib/pyplot.py\", line 950, in gca\r\n    return gcf().gca(**kwargs)\r\n  File \"/usr/local/lib/python2.7/dist-packages/matplotlib/pyplot.py\", line 586, in gcf\r\n    return figure()\r\n  File \"/usr/local/lib/python2.7/dist-packages/matplotlib/pyplot.py\", line 535, in figure\r\n    **kwargs)\r\n  File \"/usr/local/lib/python2.7/dist-packages/matplotlib/backends/backend_qt4agg.py\", line 46, in new_figure_manager\r\n    return new_figure_manager_given_figure(num, thisFig)\r\n  File \"/usr/local/lib/python2.7/dist-packages/matplotlib/backends/backend_qt4agg.py\", line 54, in new_figure_manager_given_figure\r\n    return FigureManagerQT(canvas, num)\r\n  File \"/usr/local/lib/python2.7/dist-packages/matplotlib/backends/backend_qt5.py\", line 488, in __init__\r\n    self.toolbar = self._get_toolbar(self.canvas, self.window)\r\n  File \"/usr/local/lib/python2.7/dist-packages/matplotlib/backends/backend_qt5.py\", line 539, in _get_toolbar\r\n    toolbar = NavigationToolbar2QT(canvas, parent, False)\r\n  File \"/usr/local/lib/python2.7/dist-packages/matplotlib/backends/backend_qt5.py\", line 585, in __init__\r\n    NavigationToolbar2.__init__(self, canvas)\r\n  File \"/usr/local/lib/python2.7/dist-packages/matplotlib/backend_bases.py\", line 2760, in __init__\r\n    self._init_toolbar()\r\n  File \"/usr/local/lib/python2.7/dist-packages/matplotlib/backends/backend_qt5.py\", line 601, in _init_toolbar\r\n    a = self.addAction(self._icon(image_file + '.png'),\r\n  File \"/usr/local/lib/python2.7/dist-packages/matplotlib/backends/backend_qt5.py\", line 591, in _icon\r\n    pm.setDevicePixelRatio(self.canvas._dpi_ratio)\r\nAttributeError: 'QPixmap' object has no attribute 'setDevicePixelRatio'\r\n\r\n\r\n\r\n","author":{"url":"https://github.com/ederollora","@type":"Person","name":"ederollora"},"datePublished":"2017-05-03T12:01:13.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":5},"url":"https://github.com/8562/matplotlib/issues/8562"}