René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: `fill_between` with `get_xaxis_transform` increases y-limits","articleBody":"### Bug summary\n\nIn matplotlib 3.10.0, using `fill_between()` with `transform=ax.get_xaxis_transform()` increases the y-limits every time it is called, and the original plot gets squeezed gradually, which did not happen in previous version (3.8.0).\n\n### Code for reproduction\n\n```Python\n#Modified from https://matplotlib.org/stable/gallery/lines_bars_and_markers/fill_between_demo.html\nimport matplotlib.pyplot as plt\nimport numpy as np\n\nfig, ax = plt.subplots()\nx = np.arange(0, 4 * np.pi, 0.01)\ny = np.sin(x)\nax.plot(x, y, color='black')\n\nthreshold = 0.75\nax.axhline(threshold, color='green', lw=2, alpha=0.7)\nfor i in range(10):\n    ax.fill_between(x + 0.5*i, 0, 1, where=y \u003e threshold, color='green', alpha=0.1, transform=ax.get_xaxis_transform())\n```\n\n### Actual outcome\n\n\u003cimg width=\"546\" height=\"413\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/429763b5-dc60-4871-918d-5d15252ae341\" /\u003e\n\n### Expected outcome\n\n\u003cimg width=\"568\" height=\"413\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/0d15974c-a3bd-4b24-a51f-903010631c34\" /\u003e\n\n### Additional information\n\nThe expected outcome is from version 3.8.0\n\n### Operating system\n\nWindow 11\n\n### Matplotlib Version\n\n3.10.0\n\n### Matplotlib Backend\n\nmodule://matplotlib_inline.backend_inline\n\n### Python version\n\nPython 3.12.11\n\n### Jupyter version\n\n7.4.4\n\n### Installation\n\nNone","author":{"url":"https://github.com/metachow","@type":"Person","name":"metachow"},"datePublished":"2025-07-16T09:29:33.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":6},"url":"https://github.com/30320/matplotlib/issues/30320"}