{"id":7882,"date":"2020-03-17T22:15:28","date_gmt":"2020-03-17T21:15:28","guid":{"rendered":"https:\/\/complex-systems-ai.com\/?page_id=7882"},"modified":"2022-12-03T23:03:47","modified_gmt":"2022-12-03T22:03:47","slug":"methode-de-cross-entropie","status":"publish","type":"page","link":"https:\/\/complex-systems-ai.com\/es\/algoritmos-probabilisticos\/metodo-de-entropia-cruzada\/","title":{"rendered":"M\u00e9todo de entrop\u00eda cruzada"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-page\" data-elementor-id=\"7882\" class=\"elementor elementor-7882\">\n\t\t\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-4c209a9 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"4c209a9\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-33 elementor-top-column elementor-element elementor-element-85f0158\" data-id=\"85f0158\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-9794b2c elementor-align-justify elementor-widget elementor-widget-button\" data-id=\"9794b2c\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<div class=\"elementor-button-wrapper\">\n\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm\" href=\"https:\/\/complex-systems-ai.com\/algorithmes-probabilistes\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Algorithmes probabilistes<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t<div class=\"elementor-column elementor-col-33 elementor-top-column elementor-element elementor-element-c4d1f70\" data-id=\"c4d1f70\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-5ec0aa5 elementor-align-justify elementor-widget elementor-widget-button\" data-id=\"5ec0aa5\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<div class=\"elementor-button-wrapper\">\n\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm\" href=\"https:\/\/complex-systems-ai.com\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Page d'accueil<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t<div class=\"elementor-column elementor-col-33 elementor-top-column elementor-element elementor-element-0ff78a2\" data-id=\"0ff78a2\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-2783955 elementor-align-justify elementor-widget elementor-widget-button\" data-id=\"2783955\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<div class=\"elementor-button-wrapper\">\n\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm\" href=\"https:\/\/fr.wikipedia.org\/wiki\/M%C3%A9thode_de_l%27entropie_crois%C3%A9e\" target=\"_blank\" rel=\"noopener\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Wiki<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-1b249342 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"1b249342\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-5f6b4b5d\" data-id=\"5f6b4b5d\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-61d38960 elementor-widget elementor-widget-text-editor\" data-id=\"61d38960\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_82_2 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Contenus<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Alternar tabla de contenidos\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/complex-systems-ai.com\/es\/algoritmos-probabilisticos\/metodo-de-entropia-cruzada\/#Methode-de-cross-entropie\" >M\u00e9thode de cross-entropie<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"Methode-de-cross-entropie\"><\/span>M\u00e9thode de cross-entropie<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p class=\"has-text-align-justify\">M\u00e9thode de cross-entropie a \u00e9t\u00e9 d\u00e9velopp\u00e9 comme une technique d&rsquo;estimation efficace pour les probabilit\u00e9s d&rsquo;\u00e9v\u00e9nements rares dans les syst\u00e8mes de simulation d&rsquo;\u00e9v\u00e9nements discrets et a \u00e9t\u00e9 adapt\u00e9 pour \u00eatre utilis\u00e9 dans l&rsquo;optimisation. Le nom de la technique vient de la m\u00e9thode de cross-entropie de Kullback-Leibler pour mesurer la quantit\u00e9 d&rsquo;informations (bits) n\u00e9cessaires pour identifier un \u00e9v\u00e9nement \u00e0 partir d&rsquo;un ensemble de probabilit\u00e9s.<\/p>\n\n<p class=\"has-text-align-justify\">La strat\u00e9gie de traitement de l&rsquo;information de l&rsquo;algorithme consiste \u00e0 \u00e9chantillonner l&rsquo;espace du probl\u00e8me et \u00e0 approximer la distribution des bonnes solutions. Ceci est r\u00e9alis\u00e9 en supposant une distribution de l&rsquo;espace du probl\u00e8me (tel que gaussien), en \u00e9chantillonnant le domaine du probl\u00e8me en g\u00e9n\u00e9rant des solutions candidates en utilisant la distribution et en mettant \u00e0 jour la distribution en fonction des meilleures solutions candidates d\u00e9couvertes. Les \u00e9chantillons sont construits par \u00e9tapes (un composant \u00e0 la fois) sur la base de la distribution r\u00e9sum\u00e9e des bonnes solutions. Au fur et \u00e0 mesure que l&rsquo;algorithme progresse, la distribution devient plus raffin\u00e9e jusqu&rsquo;\u00e0 ce qu&rsquo;elle se concentre sur le domaine ou la port\u00e9e des solutions optimales dans le domaine.<\/p>\n\n<p class=\"has-text-align-justify\">L&rsquo;algorithme suivant d\u00e9crit la m\u00e9thode de cross-entropie pour minimiser une fonction de co\u00fbt.<\/p>\n\n<figure class=\"wp-block-image size-large\"><img fetchpriority=\"high\" decoding=\"async\" class=\"aligncenter wp-image-7878 size-full\" src=\"https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2020\/03\/ce.png\" alt=\"M\u00e9thode de cross-entropie\" width=\"696\" height=\"713\" title=\"\" srcset=\"https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2020\/03\/ce.png 696w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2020\/03\/ce-293x300.png 293w\" sizes=\"(max-width: 696px) 100vw, 696px\" \/><\/figure>\n\n<p class=\"has-text-align-justify\">La m\u00e9thode de cross-entropie a \u00e9t\u00e9 adapt\u00e9e aux probl\u00e8mes d&rsquo;optimisation combinatoire, bien qu&rsquo;elle ait \u00e9t\u00e9 appliqu\u00e9e \u00e0 l&rsquo;optimisation de fonction continue ainsi qu&rsquo;aux probl\u00e8mes de simulation contenant beaucoup de bruits.<\/p>\n\n<p class=\"has-text-align-justify\">Un param\u00e8tre alpha (a) ou un taux d&rsquo;apprentissage dans [0; 1] est g\u00e9n\u00e9ralement r\u00e9gl\u00e9 \u00e0 un niveau \u00e9lev\u00e9, tel que 0,7. Une fonction de lissage peut \u00eatre utilis\u00e9e pour contr\u00f4ler davantage les mises \u00e0 jour de la ou des distribution(s) des \u00e9chantillons de l&rsquo;espace de d\u00e9finition. Par exemple, dans l&rsquo;optimisation d&rsquo;une fonction continue, un param\u00e8tre peut remplacer (a) pour la mise \u00e0 jour de l&rsquo;\u00e9cart-type, calcul\u00e9 au temps t comme B-B(1-1\/t)^q, o\u00f9 B est initialement r\u00e9gl\u00e9 dans [0,8; 0,99] et q est un petit entier dans [5; 10].<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Algoritmos probabil\u00edsticos P\u00e1gina de inicio Wiki M\u00e9todo de entrop\u00eda cruzada El m\u00e9todo de entrop\u00eda cruzada fue desarrollado como una t\u00e9cnica de estimaci\u00f3n eficiente para las probabilidades de eventos raros en \u2026 <\/p>","protected":false},"author":1,"featured_media":0,"parent":7129,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-7882","page","type-page","status-publish","hentry"],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/complex-systems-ai.com\/es\/wp-json\/wp\/v2\/pages\/7882","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/complex-systems-ai.com\/es\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/complex-systems-ai.com\/es\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/complex-systems-ai.com\/es\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/complex-systems-ai.com\/es\/wp-json\/wp\/v2\/comments?post=7882"}],"version-history":[{"count":5,"href":"https:\/\/complex-systems-ai.com\/es\/wp-json\/wp\/v2\/pages\/7882\/revisions"}],"predecessor-version":[{"id":18888,"href":"https:\/\/complex-systems-ai.com\/es\/wp-json\/wp\/v2\/pages\/7882\/revisions\/18888"}],"up":[{"embeddable":true,"href":"https:\/\/complex-systems-ai.com\/es\/wp-json\/wp\/v2\/pages\/7129"}],"wp:attachment":[{"href":"https:\/\/complex-systems-ai.com\/es\/wp-json\/wp\/v2\/media?parent=7882"}],"curies":[{"name":"gracias","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}