René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Better bivariate and multivariate colormaps","articleBody":"Project https://github.com/orgs/matplotlib/projects/9, which resolves github.com/matplotlib/matplotlib/issues/14168 is divided into a number of milestones, of which this is one (highlighted in bold).\n\n* Classes for bivariate and multivariate colormaps\n* `Colorizer` and `ColorizingArtist` to replace `ScalarMappable` and handle the norm→color pipeline\n* A `MultiNorm` class to handle the normalization of data for bivariate and multivariate colormaps\n* Ensure the `Colorizer` and `ColorizingArtist` work with `MultiNorm`, `BivarColormap` and `MultivarColormap`\n* Expose the new functionality via the top-level plotting functions: `imshow()`, `pcolor()` and `pcolormesh()`\n* Create equivalents to `fig.colorbar()` for `BivarColormap` and `MultivarColormap` to work with `ColorizingArtist`\n* **Select bivariate and multivariate colormaps to include in matplotlib**\n* Examples demonstrating the new functionality\n\n----\n\nWith the inclusion of https://github.com/matplotlib/matplotlib/pull/28454, matplotlib has support for `BivarColormap` and `MultivarColormap`. Two examples of  `BivarColormap` and three of `MultivarColormap` were included:\n\nBivariate:\n\u003cimg width=\"452\" height=\"415\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/7d8f6841-93df-49f5-8b9e-1e5d5a619602\" /\u003e\n\n\u003cimg width=\"452\" height=\"415\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/4e181f2e-52d8-4cf9-b0ed-df8c90290959\" /\u003e\n\nMultivariate, 2 channels, additive:\n\u003cimg width=\"452\" height=\"249\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/66c6f241-d5e0-43c6-a270-cfc62531a515\" /\u003e\n\nMultivariate, 2 channels, subtractive:\n\u003cimg width=\"452\" height=\"249\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/02c6c78f-ad3a-4355-8b4b-2bd408203cd1\" /\u003e\n\nMultivariate, 3 channels, additive:\n\u003cimg width=\"452\" height=\"381\" alt=\"Image\" src=\"https://github.com/user-attachments/assets/5dbc2168-96df-4b8a-b86f-b4f00bd1a6cf\" /\u003e\n\n---\n\nThese are insufficient for real-world use, and more colormaps are required, with more varied use cases.","author":{"url":"https://github.com/trygvrad","@type":"Person","name":"trygvrad"},"datePublished":"2025-09-08T12:49:30.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/30528/matplotlib/issues/30528"}