René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: pcolormesh is not responsive in Matplotlib 3.5","articleBody":"### Bug summary\n\nAfter updating to mpl 3.5.0 my program hangs after plotting with pcolormesh(), no error messages. It works fine witl mpl 3.3.3. When I reduce the nx,ny values in my program it works fine.\n\n### Code for reproduction\n\n```python\nimport numpy as np\r\n    import matplotlib.pyplot as plt\r\n    import cartopy.io.img_tiles as cimgt\r\n    import cartopy.crs as ccrs\r\n\r\n    fig, ax1 = plt.subplots(num=\"TestXX\", figsize=(30/2.54, 25/2.54))\r\n    \r\n    #add a map of the Netherlands\r\n    request = cimgt.OSM()\r\n    ax1=plt.axes(projection=request.crs)\r\n    ax1.set_extent([3.25, 7.35, 50.45, 53.55],ccrs.PlateCarree())\r\n    ax1.add_image(request, 10)\r\n    \r\n    #create a rectangular grid a little smaller than the map\r\n    #with cell sizes of 0.01 degree filled with random values\r\n    nx=400\r\n    ny=300\r\n    xedges=np.linspace(3.3, 7.3, nx)\r\n    yedges=np.linspace(50.5, 53.5, ny)\r\n    zvalues=np.random.random((nx, ny))\r\n    \r\n    ax1.pcolormesh(xedges, yedges, zvalues.T ,\\\r\n                   alpha=0.3, shading='auto', transform=ccrs.PlateCarree())\r\n        \r\n    plt.show()\n```\n\n\n### Actual outcome\n\nProgram hangs. Toolbar doesn't response. Hourglass is visible. No errors. \r\n![image](https://user-images.githubusercontent.com/72066686/145592426-773429fd-c256-411d-bc67-edf683996b06.png)\r\n\n\n### Expected outcome\n\nPlot has been made. Toolbar works, normal running program.\r\n![image](https://user-images.githubusercontent.com/72066686/145591331-014c04db-f9f3-4dc7-8808-64e213218fe8.png)\r\n\n\n### Additional information\n\nIt worked fine with matplotlib 3.3.3. I can then increase nx,ny to 8000,6000.(I didn't try higher values)\r\nIt seems that there is a  'problem' with pcolormesh(). \r\nIt works fine in mpl 3.5.0 with reduced nx,ny values(i.e. 100,75)\n\n### Operating system\n\nWindows 10\n\n### Matplotlib Version\n\n3.3.3 and 3.5.0\n\n### Matplotlib Backend\n\nQt5Agg\n\n### Python version\n\nPython 3.8.12\n\n### Jupyter version\n\n_No response_\n\n### Installation\n\nconda","author":{"url":"https://github.com/Hermeij","@type":"Person","name":"Hermeij"},"datePublished":"2021-12-10T14:53:57.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":10},"url":"https://github.com/21917/matplotlib/issues/21917"}