René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: matplotlib.pyplot.clf is very slow","articleBody":"### Bug summary\n\nFor relatively simple plotting examples the `plt.clf()` command can take over 30% of the calculation time. One would expect that a clear command is relatively simple and takes a limited amount of time\n\n### Code for reproduction\n\n```python\nimport numpy as np\r\nimport time\r\nimport matplotlib\r\nimport matplotlib.pyplot as plt\r\nprint(matplotlib.__version__)\r\n\r\ndef profile_expression(expression):\r\n    import cProfile  \r\n    import tempfile\r\n    import os\r\n    import subprocess\r\n    tmpdir = tempfile.mkdtemp()\r\n    statsfile = os.path.join(tmpdir, \"profile_expression_stats\")\r\n    print(\"profile_expression: running\")\r\n    t0 = time.perf_counter()\r\n    cProfile.run(expression, statsfile)\r\n    dt = time.perf_counter() - t0\r\n    print(f\"profiling: {dt:.2f} [s]\")\r\n    r = subprocess.Popen([\"snakeviz\", statsfile])\r\n    return r\r\n\r\nx=np.linspace(0, 10, 1000)\r\ny=np.linspace(0, 20, 1000)**0.1\r\n\r\ndef go():\r\n    for ii in range(5):\r\n        plt.figure(100); \r\n        plt.clf()\r\n        plt.plot(x, y, '.', label='n')\r\n        plt.plot(x, y+x, '.-', label='m')\r\n        plt.xlabel('dsf')\r\n        plt.title('sdfs')\r\n        plt.legend()\r\n        plt.draw()\r\n\r\nif __name__=='__main__':\r\n    profile_expression('go()')\n```\n\n\n### Actual outcome\n\nThe output of the minimal example (which requires https://github.com/jiffyclub/snakeviz to be installed) is a profiling graph of the code executed in the minimal example:\r\n\r\n![image](https://user-images.githubusercontent.com/883786/187289227-dbb585b2-c250-4407-af9f-649d0fe2be66.png)\r\n\r\n\n\n### Expected outcome\n\nThe `plt.clf()` should be very fast compared to the actual plotting. Going into the details of the profiling results shows a large amount of time being spend in `axis.reset_ticks`. \r\n\n\n### Additional information\n\n_No response_\n\n### Operating system\n\nWindows\n\n### Matplotlib Version\n\n3.6.0.dev3058+g87197156eb\n\n### Matplotlib Backend\n\nQt5Agg\n\n### Python version\n\n 3.10.0\n\n### Jupyter version\n\n_No response_\n\n### Installation\n\ngit checkout","author":{"url":"https://github.com/eendebakpt","@type":"Person","name":"eendebakpt"},"datePublished":"2022-08-29T20:18:15.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":8},"url":"https://github.com/23771/matplotlib/issues/23771"}