{"id":6286,"date":"2024-03-20T09:54:01","date_gmt":"2024-03-20T13:54:01","guid":{"rendered":"https:\/\/blogs.mathworks.com\/videos\/?p=6286"},"modified":"2024-03-20T09:54:01","modified_gmt":"2024-03-20T13:54:01","slug":"switching-a-parfor-to-a-parfeval","status":"publish","type":"post","link":"https:\/\/blogs.mathworks.com\/videos\/2024\/03\/20\/switching-a-parfor-to-a-parfeval\/","title":{"rendered":"Switching a parfor to a parfeval"},"content":{"rendered":"<p>I use <tt>parfor<\/tt> a lot when processing large amounts of data. It could be on my local machine, or it could be on a remote cluster. It is very simple to convert a <tt>for<\/tt> loop to a <tt>parfor<\/tt> loop and often you do not need to change the code in your loop.<\/p>\n<p>A <tt>parfor<\/tt> is efficient when the work required for each iteration is similar, but if it&#8217;s not, then, near the end of your loop, some workers can become idle. This is where <tt>parfeval<\/tt>can be helpful. It&#8217;s a little more complicated to use, but it will keep all workers busy until the work is finished. As a result, you should get your calculation finished sooner.<\/p>\n<p>Here I take a <tt>parfor<\/tt> loop in one of my existing scripts, and attempt to convert it to use <tt>parfeval<\/tt> instead.<\/p>\n<p>Features covered in this <a href=\"https:\/\/blogs.mathworks.com\/videos\/2015\/10\/29\/matlab-code-along-videos\/\">code-along<\/a> style video include:<\/p>\n<ul>\n<li><tt>parfor<\/tt><\/li>\n<li><tt>parfeval<\/tt>, <tt>FevalFuture<\/tt><\/li>\n<\/ul>\n<p><div class=\"row\"><div class=\"col-xs-12 containing-block\"><div class=\"bc-outer-container add_margin_20\"><videoplayer><div class=\"video-js-container\"><video data-video-id=\"6349319049112\" data-video-category=\"blog\" data-autostart=\"false\" data-account=\"62009828001\" data-omniture-account=\"mathwgbl\" data-player=\"rJ9XCz2Sx\" data-embed=\"default\" id=\"mathworks-brightcove-player\" class=\"video-js\" controls><\/video><script src=\"\/\/players.brightcove.net\/62009828001\/rJ9XCz2Sx_default\/index.min.js\"><\/script><script>if (typeof(playerLoaded) === 'undefined') {var playerLoaded = false;}(function isVideojsDefined() {if (typeof(videojs) !== 'undefined') {videojs(\"mathworks-brightcove-player\").on('loadedmetadata', function() {playerLoaded = true;});} else {setTimeout(isVideojsDefined, 10);}})();<\/script><\/div><\/videoplayer><\/div><\/div><\/div><\/p>\n<p>Play the video in full screen mode for a better viewing experience.\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"<div class=\"thumbnail thumbnail_asset asset_overlay video\"><a href=\"https:\/\/blogs.mathworks.com\/videos\/2024\/03\/20\/switching-a-parfor-to-a-parfeval\/?dir=autoplay\"><img decoding=\"async\" src=\"https:\/\/cf-images.us-east-1.prod.boltdns.net\/v1\/static\/62009828001\/6b834956-1ae2-4774-9f10-cc5e2891ede5\/78a9c2e4-d262-4144-b942-16bd45e57bb6\/1280x720\/match\/image.jpg\" onError=\"this.style.display ='none';\"\/><\/p>\n<div class=\"overlay_container\">\n      <span class=\"icon-video icon_color_null\"><time class=\"video_length\">16:57<\/time><\/span>\n      <\/div>\n<p>      <\/a><\/div>\n<p>I use parfor a lot when processing large amounts of data. It could be on my local machine, or it could be on a remote cluster. It is very simple to convert a for loop to a parfor loop and often you&#8230; <a class=\"read-more\" href=\"https:\/\/blogs.mathworks.com\/videos\/2024\/03\/20\/switching-a-parfor-to-a-parfeval\/\">read more >><\/a><\/p>\n","protected":false},"author":133,"featured_media":6295,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[27,4],"tags":[],"_links":{"self":[{"href":"https:\/\/blogs.mathworks.com\/videos\/wp-json\/wp\/v2\/posts\/6286"}],"collection":[{"href":"https:\/\/blogs.mathworks.com\/videos\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.mathworks.com\/videos\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.mathworks.com\/videos\/wp-json\/wp\/v2\/users\/133"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.mathworks.com\/videos\/wp-json\/wp\/v2\/comments?post=6286"}],"version-history":[{"count":8,"href":"https:\/\/blogs.mathworks.com\/videos\/wp-json\/wp\/v2\/posts\/6286\/revisions"}],"predecessor-version":[{"id":6357,"href":"https:\/\/blogs.mathworks.com\/videos\/wp-json\/wp\/v2\/posts\/6286\/revisions\/6357"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.mathworks.com\/videos\/wp-json\/wp\/v2\/media\/6295"}],"wp:attachment":[{"href":"https:\/\/blogs.mathworks.com\/videos\/wp-json\/wp\/v2\/media?parent=6286"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.mathworks.com\/videos\/wp-json\/wp\/v2\/categories?post=6286"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.mathworks.com\/videos\/wp-json\/wp\/v2\/tags?post=6286"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}