René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"\"Qualitative\" colormaps represented as continuous","articleBody":"[I'm learning about all the colormaps to update the documentation](https://gist.github.com/2719900). and it seems some were copied from ColorBrewer and converted into continuous smoothly-varying maps.  But ColorBrewer has 3 types of schemes:\n\n\u003e 1. Sequential palettes are suited to ordered data that progress from low to high. Lightness steps dominate the look of these schemes, with light colors for low data values to dark colors for high data values.\n\u003e 2. Diverging palettes put equal emphasis on mid-range critical values and extremes at both ends of the data range. The critical class or break in the middle of the legend is emphasized with light colors and low and high extremes are emphasized with dark colors that have contrasting hues.\n\u003e 3. Qualitative palettes do not imply magnitude differences between legend classes, and hues are used to create the primary visual differences between classes. Qualitative schemes are best suited to representing nominal or categorical data. \n\n![diverging, sequential, qualitative](http://andrewgelman.com/movabletype/mlm/palettes.png)\n![qualitative map](http://www.personal.psu.edu/cab38/ColorSch/SchHTMLs/Eg01-qual.gif)\n\nSo the \"qualitative\" maps (Accent, Dark2, Paired, Pastel1, Pastel2, Set1, Set2, Set3) should not be smoothly-varying.\n\nhttp://rgm2.lab.nig.ac.jp/RGM2/func.php?rd_id=RColorBrewer:ColorBrewer\n\nIt's possible to convert these to segmented maps: https://gist.github.com/2719900#file_accent.py\n\n![Accent continuous vs segmented](http://i.imgur.com/crEDx.png)\n\nShould I go through them and do that and submit a patch?  I'm not sure if the matplotlib colormaps are even meant to be used for categorical data like this.\n","author":{"url":"https://github.com/endolith","@type":"Person","name":"endolith"},"datePublished":"2012-05-18T19:38:42.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":5},"url":"https://github.com/881/matplotlib/issues/881"}