René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: Wrong scaling of `NonUniformImage` with logarithmic axes","articleBody":"### Bug summary\n\nI'm trying to produce a density plot of logarithmically spaced data. Using `NonUniformImage` used to work before matplotlib version `3.10`, where I know exhibit a weirdly scaled axis.\n\n### Code for reproduction\n\n```Python\nimport numpy as np\r\nimport matplotlib.pyplot as plt\r\nfrom matplotlib.image import NonUniformImage\r\n\r\nx = np.linspace(0, 1, 2)\r\ny = np.geomspace(1e1, 1e5, 3)\r\nz = np.random.uniform(size=(len(x), len(y)))\r\n\r\n_, (ax1, ax2) = plt.subplots(ncols=2)\r\n\r\n# create the non-uniform image\r\nim = NonUniformImage(ax1, extent=[0, 1, 1e0, 1e6], origin=\"lower\")\r\nim.set_data(x, y, z.T)\r\nax1.add_image(im)\r\nax1.set_yscale(\"log\")\r\nax1.set_ylim(1e0, 1e6)  # omitting this leads to very weird behavior\r\nax1.set_title(\"NonUniformImage\")\r\n\r\n# use pcolormesh to get reference image\r\nax2.pcolormesh([0, 0.5, 1], [1e0, 1e2, 1e4, 1e6], z.T)\r\nax2.set_yscale(\"log\")\r\nax2.set_title(\"pcolormesh\")\n```\n\n\n### Actual outcome\n\nThe code above produces the following image\r\n\r\n![b32e9b79-dd12-44f9-b472-6ef09f886ac3](https://github.com/user-attachments/assets/7c1f3d22-d35d-4b23-87d0-57d39448e4fa)\r\n\n\n### Expected outcome\n\nI expect the left panel to look like the right panel, which was produced using `pcolormesh`. The reason I don't want to use `pcolormesh` for these plots is that the quality in PDFs is often much worse (with lines showing up between patches) and the file size can easily be 10 times larger.\n\n### Additional information\n\nI recently asked [a related question on Stackoverflow](https://stackoverflow.com/q/79261313/932593), which has some additional details.\n\n### Operating system\n\nOS/X\n\n### Matplotlib Version\n\n3.10.0\n\n### Matplotlib Backend\n\nmodule://matplotlib_inline.backend_inline\n\n### Python version\n\n3.12.8\n\n### Jupyter version\n\n7.3.1\n\n### Installation\n\nconda","author":{"url":"https://github.com/david-zwicker","@type":"Person","name":"david-zwicker"},"datePublished":"2024-12-21T12:50:57.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":13},"url":"https://github.com/29368/matplotlib/issues/29368"}