René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: stacked histogram does not properly handle edgecolor and hatches","articleBody":"### Bug summary\r\n\r\nWhen using stacked histogram in matplotlib 3.7.2 the functionality of hatch and edgecolor is broken. It simply gives an error if trying to define either a separate edgecolor or hatch value for the stacked parts of the histogram.\r\n\r\n### Code for reproduction\r\n\r\n```python\r\nimport matplotlib.pyplot as plt\r\nimport numpy as np\r\n\r\nplt.hist([np.random.uniform(size=100), np.random.uniform(size=50)],\r\n         stacked=True,\r\n         color=[\"C0\", \"C1\"],\r\n         edgecolor='black',\r\n         hatch=[\"/\", \".\"],\r\n         linewidth=1,\r\n         fill=True,\r\n         density=False, \r\n         )\r\n```\r\n\r\n\r\n### Actual outcome\r\n\r\n\u003e Traceback (most recent call last):\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/IPython/core/interactiveshell.py\", line 3460, in run_code\r\n\u003e     exec(code_obj, self.user_global_ns, self.user_ns)\r\n\u003e   File \"\u003cipython-input-11-3f15e200502a\u003e\", line 1, in \u003cmodule\u003e\r\n\u003e     plt.hist([np.random.uniform(size=100), np.random.uniform(size=50)],\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/matplotlib/pyplot.py\", line 2645, in hist\r\n\u003e     return gca().hist(\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/matplotlib/__init__.py\", line 1446, in inner\r\n\u003e     return func(ax, *map(sanitize_sequence, args), **kwargs)\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/matplotlib/axes/_axes.py\", line 6944, in hist\r\n\u003e     p._internal_update(kwargs)\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/matplotlib/artist.py\", line 1223, in _internal_update\r\n\u003e     return self._update_props(\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/matplotlib/artist.py\", line 1199, in _update_props\r\n\u003e     ret.append(func(v))\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/matplotlib/patches.py\", line 525, in set_hatch\r\n\u003e     mhatch._validate_hatch_pattern(hatch)\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/matplotlib/hatch.py\", line 188, in _validate_hatch_pattern\r\n\u003e     invalids = ''.join(sorted(invalids))\r\n\u003e TypeError: sequence item 0: expected str instance, NoneType found\r\n\r\n\r\nWhile using different edgecolors for the stacked part with \r\n\r\n```\r\nplt.hist([np.random.uniform(size=100), np.random.uniform(size=50)],\r\n         stacked=True,\r\n         color=[\"C0\", \"C1\"],\r\n         edgecolor=[\"C2\", \"C3\"],\r\n         hatch=\"/\",\r\n         linewidth=1,\r\n         fill=True,\r\n         density=False, \r\n         )\r\n```\r\n\r\ndelivers the error\r\n\r\n\u003e Traceback (most recent call last):\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/IPython/core/interactiveshell.py\", line 3460, in run_code\r\n\u003e     exec(code_obj, self.user_global_ns, self.user_ns)\r\n\u003e   File \"\u003cipython-input-16-4bdbf23ac913\u003e\", line 1, in \u003cmodule\u003e\r\n\u003e     plt.hist([np.random.uniform(size=100), np.random.uniform(size=50)],\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/matplotlib/pyplot.py\", line 2645, in hist\r\n\u003e     return gca().hist(\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/matplotlib/__init__.py\", line 1446, in inner\r\n\u003e     return func(ax, *map(sanitize_sequence, args), **kwargs)\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/matplotlib/axes/_axes.py\", line 6944, in hist\r\n\u003e     p._internal_update(kwargs)\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/matplotlib/artist.py\", line 1223, in _internal_update\r\n\u003e     return self._update_props(\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/matplotlib/artist.py\", line 1199, in _update_props\r\n\u003e     ret.append(func(v))\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/matplotlib/patches.py\", line 341, in set_edgecolor\r\n\u003e     self._set_edgecolor(color)\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/matplotlib/patches.py\", line 327, in _set_edgecolor\r\n\u003e     self._edgecolor = colors.to_rgba(color, self._alpha)\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/matplotlib/colors.py\", line 299, in to_rgba\r\n\u003e     rgba = _to_rgba_no_colorcycle(c, alpha)\r\n\u003e   File \"/opt/anaconda3/envs/code/lib/python3.10/site-packages/matplotlib/colors.py\", line 383, in _to_rgba_no_colorcycle\r\n\u003e     raise ValueError(\"RGBA sequence should have length 3 or 4\")\r\n\u003e ValueError: RGBA sequence should have length 3 or 4\r\n\r\nIt seems to interpret the list of `edgecolor` [\"C2\", \"C3\"] as one color, although it is able to manage similar input for `color`.\r\n\r\n### Expected outcome\r\n\r\nIt should look similar to the following example, except that the top orange part should have dots and not slanted lines:\r\n![test_bugreport](https://github.com/matplotlib/matplotlib/assets/43748463/d29ca5f2-3f89-4c57-a608-edb4aba302ce)\r\nThe code used to generate this plot:\r\n\r\n```\r\nimport matplotlib.pyplot as plt\r\nimport numpy as np\r\nplt.hist([np.random.uniform(size=100), np.random.uniform(size=50)],\r\n         stacked=True,\r\n         color=[\"C0\", \"C1\"],\r\n         edgecolor='black',\r\n         hatch=\"/\",\r\n         linewidth=1,\r\n         fill=True,\r\n         density=False, \r\n         )\r\n```\r\n\r\nIn case of the second example it should habe two different edgecolors for the first and second part of the stacked histogram.\r\n\r\n### Additional information\r\n\r\n_No response_\r\n\r\n### Operating system\r\n\r\nMacOSX\r\n\r\n### Matplotlib Version\r\n\r\n3.7.2\r\n\r\n### Matplotlib Backend\r\n\r\nMacOSX\r\n\r\n### Python version\r\n\r\n3.10.0\r\n\r\n### Jupyter version\r\n\r\n_No response_\r\n\r\n### Installation\r\n\r\nconda","author":{"url":"https://github.com/marcelernst","@type":"Person","name":"marcelernst"},"datePublished":"2023-09-07T21:11:20.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":5},"url":"https://github.com/26718/matplotlib/issues/26718"}