René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: diagonal lines in pcolormesh with Gouraud shading and transparency","articleBody":"### Bug summary\n\nDiagonal and box lines are produced by `pcolormesh` using a cmap with transparency.\r\n\n\n### Code for reproduction\n\n```python\nimport matplotlib.colors as m_colors\r\nimport matplotlib.pyplot as plt\r\nimport numpy as np\r\nplt.pcolormesh(np.array([[0, 1, 2], [0, 1, 2]]),\r\n               np.array([[0, 0, 0], [1, 1, 1]]),\r\n               np.array([[0, 1, 2], [0, 1, 2]]),\r\n               cmap=m_colors.LinearSegmentedColormap.from_list(\r\n                   \"\", [(0, 0, 0, 0), (0, 0, 0, 1)]),\r\n               shading=\"gouraud\")\r\nplt.plot()\n```\n\n\n### Actual outcome\n\n![Figure_1](https://github.com/matplotlib/matplotlib/assets/117669574/714801d4-035a-4869-aab5-95f24e309034)\r\n\n\n### Expected outcome\n\nNo diagonal or box lines should appear.\n\n### Additional information\n\n_No response_\n\n### Operating system\n\n_No response_\n\n### Matplotlib Version\n\n3.6.2\n\n### Matplotlib Backend\n\nQtAgg\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/limwz01","@type":"Person","name":"limwz01"},"datePublished":"2023-10-06T13:45:20.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":6},"url":"https://github.com/27016/matplotlib/issues/27016"}