{"id":456,"date":"2015-07-12T12:51:37","date_gmt":"2015-07-12T12:51:37","guid":{"rendered":"http:\/\/ahay.org\/blog\/?p=456"},"modified":"2015-08-05T02:42:53","modified_gmt":"2015-08-05T02:42:53","slug":"more-colormaps","status":"publish","type":"post","link":"https:\/\/ahay.org\/blog\/2015\/07\/12\/more-colormaps\/","title":{"rendered":"More colormaps"},"content":{"rendered":"<p>The most popular colormap in Madagascar, other than the default greyscale, is <strong>color=j<\/strong>, modeled after &#8220;<strong>jet<\/strong>&#8220;, which used to be the default colormap in MATLAB. More than 1,000 Madagascar examples use <strong>color=j<\/strong>. In October 2014, with release R2014b (Version 8.4), MATLAB <a href=\"http:\/\/blogs.mathworks.com\/steve\/2014\/10\/13\/a-new-colormap-for-matlab-part-1-introduction\/\">switched the default colormap<\/a> to a different one, called &#8220;<strong>parula<\/strong>&#8220;. The &#8220;<strong>parula<\/strong>&#8221; colormap is copyrighted by MathWorks as a result of a creative process (solving an optimization problem). No open-source license is given to use it outside of MATLAB. According to Steve Eddins, &#8220;this colormap is MathWorks intellectual property, and it would not be appropriate or acceptable to copy or re-use it in non-MathWorks plotting tools.&#8221; <a href=\"http:\/\/bids.berkeley.edu\/people\/st%C3%A9fan-van-der-walt\">St\u00e9fan van der Walt<\/a> and <a href=\"http:\/\/bids.berkeley.edu\/people\/nathaniel-smith\">Nathaniel Smith<\/a> from the <a href=\"http:\/\/bids.berkeley.edu\/\">Berkeley Institute for Data Science<\/a> have developed <a href=\"https:\/\/github.com\/bids\/colormap\">several new open-source colormaps<\/a> with good perceptual properties. One of them (named &#8220;<strong>viridis<\/strong>&#8220;) is proposed as a good replacement for &#8220;<strong>jet<\/strong>&#8221; and as the default colormap in <a href=\"http:\/\/matplotlib.org\/\">matplotlib<\/a> 2.0. <img decoding=\"async\" src=\"\/RSF\/book\/rsf\/rsf\/sfgrey\/Fig\/viridis.png\" alt=\"\" title=\"\" \/> Is it a good colormap? We can find out by using tools from <a href=\"\/blog\/2014\/10\/18\/tutorial-on-colormaps\/\">Matteo Niccoli&#8217;s tutorial on colormaps<\/a>. <img decoding=\"async\" src=\"\/RSF\/book\/rsf\/tutorials\/colormaps\/Fig\/viridis-intensity2.png\" alt=\"\" title=\"\" \/><img decoding=\"async\" src=\"\/RSF\/book\/rsf\/tutorials\/colormaps\/Fig\/viridis-l.png\" alt=\"\" title=\"\" \/><img decoding=\"async\" src=\"\/RSF\/book\/rsf\/tutorials\/colormaps\/Fig\/pyramid3d-viridis.png\" alt=\"\" title=\"\" \/> This analysis shows the intensity and lightness distributions of &#8220;<strong>viridis<\/strong>&#8221; are nicely linear. In his presentation at <a href=\"http:\/\/scipy2015.scipy.org\/\">SciPy-2015<\/a>, Nathaniel Smith explains the rational for this choice. <iframe loading=\"lazy\" allowfullscreen=\"\" frameborder=\"0\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/xAoljeRJ3lU?list=PLYx7XA2nY5Gcpabmu61kKcToLz0FapmHu\" width=\"560\"><\/iframe><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The most popular colormap in Madagascar, other than the default greyscale, is color=j, modeled after &#8220;jet&#8220;, which used to be the default colormap in MATLAB. More than 1,000 Madagascar examples use color=j. In October 2014, with release R2014b (Version 8.4), MATLAB switched the default colormap to a different one, called &#8220;parula&#8220;. The &#8220;parula&#8221; colormap is [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","activitypub_content_warning":"","activitypub_content_visibility":"local","activitypub_max_image_attachments":4,"activitypub_interaction_policy_quote":"","footnotes":""},"categories":[6],"tags":[],"class_list":["post-456","post","type-post","status-publish","format-standard","hentry","category-systems"],"_links":{"self":[{"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/posts\/456","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/comments?post=456"}],"version-history":[{"count":3,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/posts\/456\/revisions"}],"predecessor-version":[{"id":925,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/posts\/456\/revisions\/925"}],"wp:attachment":[{"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/media?parent=456"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/categories?post=456"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/tags?post=456"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}