René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: Setting aspect back to auto cannot recover the original 3D plot","articleBody":"### Bug summary\n\nThis bug arises when I plot filled contours with 3d projection and auto aspect,  and save the figure as '3d-plot1.png'. Then, I set the aspect to `'equal'` and back to `'auto'`, and save the figure as '3d-plot2.png', which is inconsistent with '3d-plot1.png'. However, this bug does not occur in 2d filled contours.\n\n### Code for reproduction\n\n```Python\nimport matplotlib.pyplot as plt\nfrom mpl_toolkits.mplot3d import axes3d\n\nfig1 = plt.figure()\nax1 = fig1.add_subplot(projection=None)\nX, Y, Z = axes3d.get_test_data()\nax1.contourf(X, Y, Z, cmap=\"coolwarm\")\nax1.set_aspect('auto')\nfig1.savefig('2d-plot1.png') # Correct\nax1.set_aspect('equal')\nax1.set_aspect('auto')\nfig1.savefig('2d-plot2.png') # Correct (consistent with 2d-plot1.png)\n\nfig2 = plt.figure()\nax2 = fig2.add_subplot(projection='3d')\nX, Y, Z = axes3d.get_test_data()\nax2.contourf(X, Y, Z, cmap=\"coolwarm\")\nax2.set_aspect('auto')\nfig2.savefig('3d-plot1.png') # Correct\nax2.set_aspect('equal')\nax2.set_aspect('auto')\nfig2.savefig('3d-plot2.png') # Wrong (inconsistent with 3d-plot1.png)\n```\n\n### Actual outcome\n\n#### 2d-plot1.png\n\n\u003cimg width=\"640\" height=\"480\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/b1a4eec5-cf8e-403a-a1cd-b9b07719d68e\" /\u003e\n\n#### 2d-plot2.png\n\n\u003cimg width=\"640\" height=\"480\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/d2a68576-5ae2-4ab4-80ee-d329009bbd31\" /\u003e\n\n#### 3d-plot1.png\n\n\u003cimg width=\"640\" height=\"480\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/0169e96b-97ca-4312-b38c-d049f5538cb3\" /\u003e\n\n#### 3d-plot2.png\n\n\u003cimg width=\"640\" height=\"480\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/e7d40002-9637-4f5f-a851-43daea06fdd0\" /\u003e\n\n### Expected outcome\n\n3d-plot2.png should be the same as 3d-plot1.png.\n\n### Additional information\n\n_No response_\n\n### Operating system\n\n_No response_\n\n### Matplotlib Version\n\n3.10.8\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/smith2936","@type":"Person","name":"smith2936"},"datePublished":"2026-03-11T07:32:56.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/31276/matplotlib/issues/31276"}