René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: Incorrect offsets and scaling of EllipseCollection","articleBody":"### Bug summary\n\nThis is a regression bug. The position and scaling of `EllipseCollection` do not follow the specification of `offsets`.\n\n### Code for reproduction\n\n```Python\nimport matplotlib.pyplot as plt\nimport numpy as np\nfrom matplotlib.collections import EllipseCollection\n\nx = np.arange(2)\ny = np.arange(2)\nX, Y = np.meshgrid(x, y)\n\nXY = np.column_stack((np.zeros_like(X.ravel()), Y.ravel()))\n\nfig, ax = plt.subplots()\n\nec = EllipseCollection(X, Y, X, units='x', offsets=XY, offset_transform=ax.transData)  \nax.add_collection(ec)\nplt.show()\n```\n\n### Actual outcome\n\n\u003cimg width=\"547\" height=\"413\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/34b3812c-611e-4622-ab89-51b9ca75a84c\" /\u003e\n\n### Expected outcome\n\n\u003cimg width=\"558\" height=\"418\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/4a34065c-c32f-4c6f-a7d1-4bd8c025a579\" /\u003e\n\n### Additional information\n\nThis works in v3.10.8.\n\n### Operating system\n\n_No response_\n\n### Matplotlib Version\n\n0.2.0.dev53474+unknown.g9e210e864\n\n### Matplotlib Backend\n\n_No response_\n\n### Python version\n\n_No response_\n\n### Jupyter version\n\n_No response_\n\n### Installation\n\nNone","author":{"url":"https://github.com/williamlus","@type":"Person","name":"williamlus"},"datePublished":"2025-12-16T07:59:47.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":4},"url":"https://github.com/30866/matplotlib/issues/30866"}