René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: (Tight) layout engine breaks for 3D patches","articleBody":"### Bug summary\r\n\r\nThe tight layout sometimes breaks for plots with 3D patches because 'PathPatch3D' object has no attribute '_path2d'.\r\n\r\n### Code for reproduction\r\n\r\n```python\r\nimport matplotlib.pyplot as plt\r\nimport matplotlib.patches as pat\r\nimport mpl_toolkits.mplot3d.art3d as art3d\r\n\r\nfig, ax = plt.subplots(subplot_kw={\"projection\": \"3d\"}, layout=\"tight\") # , dpi=300)\r\n\r\np = pat.Rectangle((0, 0), 1.0, 1.0)\r\nax.add_patch(p)\r\nart3d.pathpatch_2d_to_3d(p)\r\n\r\n# fig.set_dpi(300)\r\n# fig.tight_layout()\r\n\r\nfig.savefig(\"test.pdf\")  #, dpi=300)\r\n```\r\n\r\n\r\n### Actual outcome\r\n```\r\nTraceback (most recent call last):\r\n  File \"/home/tobias/mne3.py\", line 11, in \u003cmodule\u003e\r\n    fig.savefig(\"test.pdf\")  #, dpi=300)\r\n    ^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"/home/tobias/.local/lib/python3.11/site-packages/matplotlib/figure.py\", line 3343, in savefig\r\n    self.canvas.print_figure(fname, **kwargs)\r\n  File \"/home/tobias/.local/lib/python3.11/site-packages/matplotlib/backends/backend_qtagg.py\", line 75, in print_figure\r\n    super().print_figure(*args, **kwargs)\r\n  File \"/home/tobias/.local/lib/python3.11/site-packages/matplotlib/backend_bases.py\", line 2342, in print_figure\r\n    self.figure.draw(renderer)\r\n  File \"/home/tobias/.local/lib/python3.11/site-packages/matplotlib/artist.py\", line 95, in draw_wrapper\r\n    result = draw(artist, renderer, *args, **kwargs)\r\n             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"/home/tobias/.local/lib/python3.11/site-packages/matplotlib/artist.py\", line 72, in draw_wrapper\r\n    return draw(artist, renderer)\r\n           ^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"/home/tobias/.local/lib/python3.11/site-packages/matplotlib/figure.py\", line 3134, in draw\r\n    self.get_layout_engine().execute(self)\r\n  File \"/home/tobias/.local/lib/python3.11/site-packages/matplotlib/layout_engine.py\", line 178, in execute\r\n    kwargs = get_tight_layout_figure(\r\n             ^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"/home/tobias/.local/lib/python3.11/site-packages/matplotlib/_tight_layout.py\", line 266, in get_tight_layout_figure\r\n    kwargs = _auto_adjust_subplotpars(fig, renderer,\r\n             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"/home/tobias/.local/lib/python3.11/site-packages/matplotlib/_tight_layout.py\", line 82, in _auto_adjust_subplotpars\r\n    bb += [martist._get_tightbbox_for_layout_only(ax, renderer)]\r\n           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"/home/tobias/.local/lib/python3.11/site-packages/matplotlib/artist.py\", line 1415, in _get_tightbbox_for_layout_only\r\n    return obj.get_tightbbox(*args, **{**kwargs, \"for_layout_only\": True})\r\n           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"/home/tobias/.local/lib/python3.11/site-packages/mpl_toolkits/mplot3d/axes3d.py\", line 3189, in get_tightbbox\r\n    ret = super().get_tightbbox(renderer,\r\n          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"/home/tobias/.local/lib/python3.11/site-packages/matplotlib/axes/_base.py\", line 4408, in get_tightbbox\r\n    bbox = a.get_tightbbox(renderer)\r\n           ^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"/home/tobias/.local/lib/python3.11/site-packages/matplotlib/artist.py\", line 367, in get_tightbbox\r\n    bbox = self.get_window_extent(renderer)\r\n           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"/home/tobias/.local/lib/python3.11/site-packages/matplotlib/patches.py\", line 604, in get_window_extent\r\n    return self.get_path().get_extents(self.get_transform())\r\n           ^^^^^^^^^^^^^^^\r\n  File \"/home/tobias/.local/lib/python3.11/site-packages/mpl_toolkits/mplot3d/art3d.py\", line 420, in get_path\r\n    return self._path2d\r\n           ^^^^^^^^^^^^\r\nAttributeError: 'PathPatch3D' object has no attribute '_path2d'\r\n```\r\n### Expected outcome\r\n\r\nThe following code actually produces (something that is at least close enough to) the expected outcome. It does **NOT** produce an error even though I would expect it to be equivalent.\r\n```python\r\nimport matplotlib.pyplot as plt\r\nimport matplotlib.patches as pat\r\nimport mpl_toolkits.mplot3d.art3d as art3d\r\n\r\nfig, ax = plt.subplots(subplot_kw={\"projection\": \"3d\"})\r\n\r\np = pat.Rectangle((0, 0), 1.0, 1.0)\r\nax.add_patch(p)\r\nart3d.pathpatch_2d_to_3d(p)\r\n\r\nfig.tight_layout()\r\n\r\nfig.savefig(\"test.pdf\")\r\n```\r\nThe result is different compared to the case without the tight layout engine, so I assume it is doing something. However I am not sure if it is fully doing it's job.\r\n\r\n### Additional information\r\n\r\nWhether I get an error or not depends on some weird circumstances (e.g. the behaviour depends on dpi settings). I left some possible modifications as comments in the minimal example above. Here is a short summary of some test I did:\r\n\r\n- `layout=\"tight\"` works with `fig.savefig(\"test.png\")` but **NOT** with `fig.savefig(\"test.png\", dpi=300)`.\r\n- Similarly if I use `plt.subplots(..., dpi=300)` or `fig.set_dpi(300)` the call to `fig.tight_layout()` already gives an error and **NOT** the call to `fig.savefig()`.\r\n- In most cases where it breaks for `layout=\"tight\"` it also breaks for `\"compressed\"` or `\"constrained\"`.\r\n\r\n### Operating system\r\n\r\nArch\r\n\r\n### Matplotlib Version\r\n\r\n3.7.1\r\n\r\n### Matplotlib Backend\r\n\r\nQtAgg\r\n\r\n### Python version\r\n\r\nPython 3.11.5\r\n\r\n### Jupyter version\r\n\r\n_No response_\r\n\r\n### Installation\r\n\r\nLinux package manager","author":{"url":"https://github.com/thrien","@type":"Person","name":"thrien"},"datePublished":"2023-11-22T19:23:45.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":8},"url":"https://github.com/27361/matplotlib/issues/27361"}