René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: Slow lasso selector over QuadMesh collection","articleBody":"### Bug summary\r\n\r\nWhen I create pcolormesh plot with big enough data, lasso selector (useblit=True) is redrawing very slowly. Don't have problem with this in version 3.4.2\r\n\r\n### Code for reproduction\r\n\r\n```python\r\nimport numpy as np\r\nfrom matplotlib.widgets import LassoSelector\r\nimport matplotlib.pyplot as plt\r\n\r\nclass SelectFromCollection:\r\n    def __init__(self, ax):\r\n        self.lasso = LassoSelector(ax, onselect=self.onselect, useblit=True)\r\n    def onselect(self, verts):\r\n        pass\r\n\r\n\r\nif __name__ == '__main__':\r\n    fig, ax = plt.subplots()\r\n\r\n    np.random.seed(19680801)\r\n    Z = np.random.rand(1095, 100)\r\n    x = np.arange(-0.5, 100, 1)  # len = 11\r\n    y = np.arange(4.5, 1100, 1)  # len = 7\r\n\r\n    ax.pcolormesh(x, y, Z)\r\n    # data2d = np.random.randint(0, 100,(1000,1000))\r\n    # ax.imshow(data2d)\r\n    selector = SelectFromCollection(ax)\r\n    plt.show()\r\n```\r\n\r\n\r\n### Actual outcome\r\n\r\nSlow lasso drawing\r\n\r\n### Expected outcome\r\n\r\nQuick lasso drawing :)\r\n\r\n### Additional information\r\n\r\nIf imshow is used, lasso selector is acting normaly.\r\n\r\n### Operating system\r\n\r\nUbuntu 20.04\r\n\r\n### Matplotlib Version\r\n\r\n3.5.1\r\n\r\n### Matplotlib Backend\r\n\r\nQtAgg\r\n\r\n### Python version\r\n\r\n3.8\r\n\r\n### Jupyter version\r\n\r\n_No response_\r\n\r\n### Installation\r\n\r\n_No response_","author":{"url":"https://github.com/Stassels","@type":"Person","name":"Stassels"},"datePublished":"2022-02-21T14:36:07.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":3},"url":"https://github.com/22520/matplotlib/issues/22520"}