{"id":23900,"date":"2020-12-29T14:56:13","date_gmt":"2020-12-29T13:56:13","guid":{"rendered":"https:\/\/datascientest.com\/?p=23900"},"modified":"2023-11-09T14:11:15","modified_gmt":"2023-11-09T14:11:15","slug":"normalisation-des-donnees","status":"publish","type":"post","link":"https:\/\/datascientest.com\/normalisation-des-donnees","title":{"rendered":"Hello Daniel, qu\u2019est-ce que la normalisation des donn\u00e9es ?"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"23900\" class=\"elementor elementor-23900\" data-elementor-post-type=\"post\">\n\t\t\t\t\t\t\t<div class=\"elementor-element elementor-element-b3ff878 e-flex e-con-boxed e-con\" data-id=\"b3ff878\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;boxed&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-0e56839 elementor-widget elementor-widget-heading\" data-id=\"0e56839\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.15.0 - 02-08-2023 *\/\n.elementor-heading-title{padding:0;margin:0;line-height:1}.elementor-widget-heading .elementor-heading-title[class*=elementor-size-]>a{color:inherit;font-size:inherit;line-height:inherit}.elementor-widget-heading .elementor-heading-title.elementor-size-small{font-size:15px}.elementor-widget-heading .elementor-heading-title.elementor-size-medium{font-size:19px}.elementor-widget-heading .elementor-heading-title.elementor-size-large{font-size:29px}.elementor-widget-heading .elementor-heading-title.elementor-size-xl{font-size:39px}.elementor-widget-heading .elementor-heading-title.elementor-size-xxl{font-size:59px}<\/style><h2 class=\"elementor-heading-title elementor-size-default\">Daniel, c\u2019est le support technique des formations DataScientest.\u00a0 C\u2019est l\u2019expert cal\u00e9 sur tous les sujets data science et qui accompagne les apprenants tout au long de leurs formations. Aujourd\u2019hui, on a r\u00e9ussi \u00e0 capter quelques minutes de son temps pr\u00e9cieux pour qu\u2019il puisse r\u00e9pondre \u00e0 nos questions autour de la normalisation des donn\u00e9es.<\/h2>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-063d565 elementor-widget elementor-widget-image\" data-id=\"063d565\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.15.0 - 02-08-2023 *\/\n.elementor-widget-image{text-align:center}.elementor-widget-image a{display:inline-block}.elementor-widget-image a img[src$=\".svg\"]{width:48px}.elementor-widget-image img{vertical-align:middle;display:inline-block}<\/style>\t\t\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"2560\" height=\"1405\" src=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/illu_hellodaniel_blog-46.png\" class=\"attachment-full size-full wp-image-29124\" alt=\"Normalisation des donn\u00e9es\" srcset=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/illu_hellodaniel_blog-46.png 2560w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/illu_hellodaniel_blog-46-300x165.png 300w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/illu_hellodaniel_blog-46-1024x562.png 1024w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/illu_hellodaniel_blog-46-768x422.png 768w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/illu_hellodaniel_blog-46-1536x843.png 1536w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/illu_hellodaniel_blog-46-2048x1124.png 2048w\" sizes=\"(max-width: 2560px) 100vw, 2560px\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-40ccb14 elementor-widget elementor-widget-heading\" data-id=\"40ccb14\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Moi - Hello Daniel je sais qu\u2019on a souvent d\u00fb te poser la question mais je vois en permanence parler de la normalisation des donn\u00e9es, est-ce que tu peux m\u2019aider \u00e0 comprendre le concept en quelques mots\u00a0?<\/h2>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-9b611f9 elementor-widget elementor-widget-text-editor\" data-id=\"9b611f9\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.15.0 - 02-08-2023 *\/\n.elementor-widget-text-editor.elementor-drop-cap-view-stacked .elementor-drop-cap{background-color:#69727d;color:#fff}.elementor-widget-text-editor.elementor-drop-cap-view-framed .elementor-drop-cap{color:#69727d;border:3px solid;background-color:transparent}.elementor-widget-text-editor:not(.elementor-drop-cap-view-default) .elementor-drop-cap{margin-top:8px}.elementor-widget-text-editor:not(.elementor-drop-cap-view-default) .elementor-drop-cap-letter{width:1em;height:1em}.elementor-widget-text-editor .elementor-drop-cap{float:left;text-align:center;line-height:1;font-size:50px}.elementor-widget-text-editor .elementor-drop-cap-letter{display:inline-block}<\/style>\t\t\t\t<p><span style=\"font-weight: 400;\"><strong>Daniel<\/strong> &#8211; Alors en effet, la normalisation, comme on l\u2019entend dans le domaine, est un <\/span><b>concept central en pr\u00e9traitement des donn\u00e9es<\/b><span style=\"font-weight: 400;\"> lorsque l\u2019on est amen\u00e9 \u00e0 travailler sur un projet de\u00a0<\/span><a href=\"https:\/\/datascientest.com\/machine-learning-tout-savoir\" target=\"_blank\" rel=\"noopener\">Machine Learning<\/a><span style=\"font-weight: 400;\">.\u00a0<\/span><\/p><p><span style=\"font-weight: 400;\">Deux principaux proc\u00e9d\u00e9s sont en r\u00e9alit\u00e9 sous-entendus lorsqu\u2019on parle de normalisation\u00a0: <\/span><b>la normalisation et la normalisation standard, ou plus commun\u00e9ment connu sous le nom de standardisation<\/b><span style=\"font-weight: 400;\">. <\/span><span style=\"font-weight: 400;\">Dans l\u2019ensemble, ces deux proc\u00e9d\u00e9s ont la m\u00eame vocation\u00a0: redimensionner les variables num\u00e9riques pour qu\u2019elles soient comparables sur une \u00e9chelle commune.\u00a0<\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d8004e8 elementor-align-center button-principale elementor-widget elementor-widget-button\" data-id=\"d8004e8\" data-element_type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-button-wrapper\">\n\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm elementor-animation-grow\" href=\"https:\/\/datascientest.com\/formation-data-scientist\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t<span class=\"elementor-button-text\">Apprendre \u00e0 normaliser les donn\u00e9es<\/span>\n\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-0188af2 e-flex e-con-boxed e-con\" data-id=\"0188af2\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;boxed&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-6ca1366 elementor-widget elementor-widget-heading\" data-id=\"6ca1366\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Et math\u00e9matiquement, \u00e7a donne quoi ?<\/h3>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-acf0a78 elementor-widget elementor-widget-text-editor\" data-id=\"acf0a78\" data-element_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<p><span style=\"color: #000000;\"><span style=\"font-weight: 400;\">Consid\u00e9rons une variable num\u00e9rique \u00e0 <\/span><i><span style=\"font-weight: 400;\">n<\/span><\/i><span style=\"font-weight: 400;\"> observations pouvant s\u2019\u00e9crire\u00a0:\u00a0<\/span><\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6ed9d3e elementor-widget elementor-widget-image\" data-id=\"6ed9d3e\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"485\" height=\"85\" src=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/cap3.png\" class=\"attachment-full size-full wp-image-24283\" alt=\"Normalisation des donn\u00e9es\" srcset=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/cap3.png 485w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/cap3-300x53.png 300w\" sizes=\"(max-width: 485px) 100vw, 485px\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ef9b8fb elementor-widget elementor-widget-text-editor\" data-id=\"ef9b8fb\" data-element_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<p><span style=\"font-weight: 400;\">Comme nous avons un nombre fini de valeurs r\u00e9elles, nous pouvons extraire plusieurs informations statistiques dont\u00a0: le <\/span><b>min<\/b><span style=\"font-weight: 400;\">,<\/span> <span style=\"font-weight: 400;\">le<\/span><b> max<\/b><span style=\"font-weight: 400;\">, la<\/span><b> moyenne <\/b><span style=\"font-weight: 400;\">et <\/span><b>l\u2019\u00e9cart type<\/b><span style=\"font-weight: 400;\">.\u00a0<\/span><\/p><p><span style=\"font-weight: 400;\">\u00a0<\/span><span style=\"font-weight: 400;\">Le proc\u00e9d\u00e9 de <\/span><b>normalisation<\/b> <span style=\"font-weight: 400;\">n\u2019a besoin que du min et du max.<\/span><\/p><blockquote><p><span style=\"font-weight: 400;\">L\u2019id\u00e9e est la suivante, on ram\u00e8ne toutes les valeurs de la variable entre 0 et 1, tout en conservant les distances entre les valeurs.<\/span><\/p><\/blockquote><p><span style=\"font-weight: 400;\">Pour ce faire rien de plus simple, la formule est la suivante\u00a0: <\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-897852d elementor-widget elementor-widget-image\" data-id=\"897852d\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"429\" height=\"109\" src=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/cap1.png\" class=\"attachment-full size-full wp-image-24278\" alt=\"Normalisation des donn\u00e9es\" srcset=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/cap1.png 429w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/cap1-300x76.png 300w\" sizes=\"(max-width: 429px) 100vw, 429px\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-19ac363 elementor-widget elementor-widget-text-editor\" data-id=\"19ac363\" data-element_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<blockquote><p><span style=\"font-weight: 400;\">Pour ce qui est de la <\/span><b>standardisation<\/b><span style=\"font-weight: 400;\">, la transformation est plus subtile que simplement ramener l\u2019ensemble des valeurs entre 0 et 1, elle a pour but de ramener <\/span><b>la moyenne <\/b><b>\u03bc<\/b><b> \u00e0 0 <\/b><span style=\"font-weight: 400;\">et <\/span><b>l\u2019\u00e9cart-type <\/b><b>\u03c3<\/b><b> \u00e0 1<\/b><span style=\"font-weight: 400;\">.<\/span><\/p><\/blockquote><p><span style=\"font-weight: 400;\">Encore une fois, le proc\u00e9d\u00e9 n\u2019est pas sorcier si on a \u00e0 disposition la moyenne <\/span><span style=\"font-weight: 400;\">\u03bc<\/span><span style=\"font-weight: 400;\"> et l\u2019\u00e9cart-type <\/span><span style=\"font-weight: 400;\">\u03c3<\/span><span style=\"font-weight: 400;\"> d\u2019une variable X = <\/span><span style=\"font-weight: 400;\">x<\/span><span style=\"font-weight: 400;\"><sub>1<\/sub><\/span> <span style=\"font-weight: 400;\">x<\/span><span style=\"font-weight: 400;\"><sub>2<\/sub><\/span> <span style=\"font-weight: 400;\">x<\/span><span style=\"font-weight: 400;\"><sub>n<\/sub><\/span> <span style=\"font-weight: 400;\"> donn\u00e9e, alors la variable standardis\u00e9e s\u2019\u00e9crira\u00a0:\u00a0<\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ec70223 elementor-widget elementor-widget-image\" data-id=\"ec70223\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"434\" height=\"122\" src=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/Capture-de\u0301cran-2020-12-30-a\u0300-16.18.58.png\" class=\"attachment-full size-full wp-image-30927\" alt=\"Normalisation des donn\u00e9es\" srcset=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/Capture-de\u0301cran-2020-12-30-a\u0300-16.18.58.png 434w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/Capture-de\u0301cran-2020-12-30-a\u0300-16.18.58-300x84.png 300w\" sizes=\"(max-width: 434px) 100vw, 434px\" \/>\t\t\t\t\t\t\t\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\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-d4298bf e-flex e-con-boxed e-con\" data-id=\"d4298bf\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;boxed&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-cad335b elementor-widget elementor-widget-heading\" data-id=\"cad335b\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">C\u2019est super tout \u00e7a, mais dans la data, \u00e0 quoi \u00e7a sert\u00a0?<\/h3>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-87e29f5 elementor-widget elementor-widget-text-editor\" data-id=\"87e29f5\" data-element_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<p><span style=\"font-weight: 400;\">Dans la data, on est tr\u00e8s souvent amen\u00e9s \u00e0 travailler avec des donn\u00e9es num\u00e9riques, et <\/span><b>ces donn\u00e9es sont rarement comparables dans leur \u00e9tat brut<\/b><span style=\"font-weight: 400;\">. <\/span><\/p><blockquote><p><span style=\"font-weight: 400;\">Travailler avec des donn\u00e9es d\u2019\u00e9chelles variables peut constituer un probl\u00e8me dans l\u2019analyse en ce sens qu\u2019une variable num\u00e9rique dont la plage de valeurs est comprise entre 0 et 10000 sera plus pesante dans l\u2019analyse qu\u2019une variable dont les valeurs sont comprises entre 0 et 1 ce qui causerait un probl\u00e8me de biais par la suite.\u00a0<\/span><\/p><\/blockquote><p><span style=\"font-weight: 400;\">Attention cependant \u00e0 ne pas consid\u00e9rer la normalisation comme une \u00e9tape obligatoire dans le traitement de nos donn\u00e9es, elle constitue une perte d\u2019information dans l\u2019imm\u00e9diat et peut desservir dans certains cas\u00a0!<\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d29bb2e elementor-align-center button-principale elementor-widget elementor-widget-button\" data-id=\"d29bb2e\" data-element_type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-button-wrapper\">\n\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm elementor-animation-grow\" href=\"https:\/\/datascientest.com\/formations-data\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t<span class=\"elementor-button-text\">En savoir plus sur les formations de la Data<\/span>\n\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-d8499b5 e-flex e-con-boxed e-con\" data-id=\"d8499b5\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;boxed&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-d864539 elementor-widget elementor-widget-heading\" data-id=\"d864539\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Je comprends mieux, mais une question reste en suspens, comment on normalise des donn\u00e9es concr\u00e8tement\u00a0?\u00a0<\/h3>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c403ac9 elementor-widget elementor-widget-text-editor\" data-id=\"c403ac9\" data-element_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<p><span style=\"font-weight: 400;\">Sur <a href=\"https:\/\/datascientest.com\/python-tout-savoir\">Python<\/a> c\u2019est tr\u00e8s simple, de nombreuses librairies le permettent. Je ne mentionnerai que\u00a0<\/span><a href=\"https:\/\/scikit-learn.org\/stable\/\" target=\"_blank\" rel=\"noopener\">Scikit-learn<\/a>,<span style=\"font-weight: 400;\">\u00a0car c\u2019est la plus utilis\u00e9e en Data Science. Cette biblioth\u00e8que propose des fonctions qui effectuent les normalisations voulues en quelques lignes de code tr\u00e8s simples.\u00a0<\/span><\/p><p><span style=\"font-weight: 400;\">Il est important n\u00e9anmoins de remettre les cas d\u2019usage en contexte, car en pratique il ne suffit pas d\u2019appliquer une normalisation b\u00eate et m\u00e9chante \u00e0 toutes les donn\u00e9es qui nous passent sous la main alors que l\u2019on a d\u00e9j\u00e0 normalis\u00e9 nos donn\u00e9es d&rsquo;entra\u00eenement.<\/span><\/p><p><span style=\"font-weight: 400;\">Pourquoi ? Pour la simple raison qu<\/span><b>&lsquo;il n&rsquo;est pas possible d&rsquo;appliquer cette m\u00eame transformation \u00e0 un \u00e9chantillon de test, ou \u00e0 des donn\u00e9es nouvelles.<\/b><\/p><p><span style=\"font-weight: 400;\">Il est possible \u00e9videmment de centrer et r\u00e9duire n&rsquo;importe quel \u00e9chantillon de la m\u00eame mani\u00e8re, mais avec une moyenne et un \u00e9cart type qui seront diff\u00e9rents de ceux utilis\u00e9s sur l&rsquo;ensemble d&rsquo;entra\u00eenement<\/span><\/p><p><span style=\"font-weight: 400;\">Les r\u00e9sultats obtenus ne seraient pas une juste repr\u00e9sentation de la performance du mod\u00e8le dans son ensemble, lorsqu&rsquo;il sera appliqu\u00e9 \u00e0 de nouvelles donn\u00e9es.<\/span><\/p><p><span style=\"font-weight: 400;\">Donc, plut\u00f4t que d&rsquo;appliquer directement la fonction de normalisation, il est pr\u00e9f\u00e9rable d&rsquo;utiliser une fonctionnalit\u00e9 de Scikit-Learn appel\u00e9e <\/span><b>Transformer API<\/b><span style=\"font-weight: 400;\">, qui vous permettra d&rsquo;ajuster <\/span><i><span style=\"font-weight: 400;\">(fit)<\/span><\/i><span style=\"font-weight: 400;\"> une \u00e9tape de preprocessing en utilisant les donn\u00e9es d&rsquo;entra\u00eenement.<\/span><\/p><p><span style=\"font-weight: 400;\">Ainsi lorsque la normalisation, par exemple, sera appliqu\u00e9e \u00e0 d&rsquo;autres \u00e9chantillons, elle utilisera les m\u00eames moyennes et \u00e9cart-types sauvegard\u00e9s.<\/span><\/p><p><span style=\"font-weight: 400;\">Pour cr\u00e9er cette <strong>\u00e9tape de preprocessing<\/strong> &lsquo;ajust\u00e9e&rsquo; il suffit d&rsquo;utiliser la fonction <strong>StandardScaler<\/strong> puis de l&rsquo;ajuster gr\u00e2ce \u00e0 aux donn\u00e9es d&rsquo;entra\u00eenement. Enfin pour l&rsquo;appliquer \u00e0 un tableau de donn\u00e9es par la suite il faudra simplement lui appliquer<strong> scaler.transform()<\/strong>.<\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-b8e0769 elementor-widget elementor-widget-shortcode\" data-id=\"b8e0769\" data-element_type=\"widget\" data-widget_type=\"shortcode.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-shortcode\"><script src=\"https:\/\/gist.github.com\/AdrienRuimy\/c24d138fe3403be1eafa4e608e9e26f8.js\"><\/script><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0adbbdc elementor-widget elementor-widget-text-editor\" data-id=\"0adbbdc\" data-element_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<p><span style=\"font-weight: 400;\"><span style=\"color: #000000;\">De m\u00eame pour une normalisation MinMax\u00a0:<\/span><\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-b4d9136 elementor-widget elementor-widget-shortcode\" data-id=\"b4d9136\" data-element_type=\"widget\" data-widget_type=\"shortcode.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-shortcode\"><\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-f5f4edb elementor-widget elementor-widget-text-editor\" data-id=\"f5f4edb\" data-element_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<p>Super, merci Daniel !\u00a0<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-284ea48 e-flex e-con-boxed e-con\" data-id=\"284ea48\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;boxed&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-9fd8ebc elementor-widget elementor-widget-heading\" data-id=\"9fd8ebc\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Si on veut se former en Data Science en \u00e9tant guid\u00e9 par tes conseils, comment on fait ?\u00a0<\/h3>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-e4e6748 elementor-widget elementor-widget-text-editor\" data-id=\"e4e6748\" data-element_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<p>Rien de plus simple, il vous suffit de d\u00e9marrer prochainement l&rsquo;une de nos <a href=\"https:\/\/datascientest.com\/formations-data\">formations en Data Science<\/a>\u00a0\ud83d\ude42\u00a0 Si vous souhaitez d\u00e9couvrir l&rsquo;apport de Daniel au cours d&rsquo;une formation, retrouvez l&rsquo;interview de deux de nos alumnis :\u00a0<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-86dc04f elementor-widget__width-initial elementor-widget elementor-widget-video\" data-id=\"86dc04f\" data-element_type=\"widget\" data-settings=\"{&quot;youtube_url&quot;:&quot;https:\\\/\\\/youtu.be\\\/KvfQXAl8BdA&quot;,&quot;video_type&quot;:&quot;youtube&quot;,&quot;controls&quot;:&quot;yes&quot;}\" data-widget_type=\"video.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.15.0 - 02-08-2023 *\/\n.elementor-widget-video .elementor-widget-container{overflow:hidden;transform:translateZ(0)}.elementor-widget-video .elementor-wrapper{aspect-ratio:var(--video-aspect-ratio)}.elementor-widget-video .elementor-wrapper iframe,.elementor-widget-video .elementor-wrapper video{height:100%;width:100%;display:flex;border:none;background-color:#000}@supports not (aspect-ratio:1\/1){.elementor-widget-video .elementor-wrapper{position:relative;overflow:hidden;height:0;padding-bottom:calc(100% \/ var(--video-aspect-ratio))}.elementor-widget-video .elementor-wrapper iframe,.elementor-widget-video .elementor-wrapper video{position:absolute;top:0;right:0;bottom:0;left:0}}.elementor-widget-video .elementor-open-inline .elementor-custom-embed-image-overlay{position:absolute;top:0;right:0;bottom:0;left:0;background-size:cover;background-position:50%}.elementor-widget-video .elementor-custom-embed-image-overlay{cursor:pointer;text-align:center}.elementor-widget-video .elementor-custom-embed-image-overlay:hover .elementor-custom-embed-play i{opacity:1}.elementor-widget-video .elementor-custom-embed-image-overlay img{display:block;width:100%;aspect-ratio:var(--video-aspect-ratio);-o-object-fit:cover;object-fit:cover;-o-object-position:center center;object-position:center center}@supports not (aspect-ratio:1\/1){.elementor-widget-video .elementor-custom-embed-image-overlay{position:relative;overflow:hidden;height:0;padding-bottom:calc(100% \/ var(--video-aspect-ratio))}.elementor-widget-video .elementor-custom-embed-image-overlay img{position:absolute;top:0;right:0;bottom:0;left:0}}.elementor-widget-video .e-hosted-video .elementor-video{-o-object-fit:cover;object-fit:cover}.e-con-inner>.elementor-widget-video,.e-con>.elementor-widget-video{width:var(--container-widget-width);--flex-grow:var(--container-widget-flex-grow)}<\/style>\t\t<div class=\"elementor-wrapper elementor-open-inline\">\n\t\t\t<div class=\"elementor-video\"><\/div>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-cef938b elementor-align-center button-principale elementor-widget elementor-widget-button\" data-id=\"cef938b\" data-element_type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-button-wrapper\">\n\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm elementor-animation-grow\" href=\"\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t<span class=\"elementor-button-text\">D\u00e9couvrir les prochaines dates<\/span>\n\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Daniel, c\u2019est le support technique des formations DataScientest.&nbsp; C\u2019est l\u2019expert cal\u00e9 sur tous les sujets data science et qui accompagne les apprenants tout au long de leurs formations. Aujourd\u2019hui, on a r\u00e9ussi \u00e0 capter quelques minutes de son temps pr\u00e9cieux pour qu\u2019il puisse r\u00e9pondre \u00e0 nos questions autour de la normalisation des donn\u00e9es. Moi &#8211; [&hellip;]<\/p>\n","protected":false},"author":78,"featured_media":30548,"comment_status":"open","ping_status":"open","sticky":false,"template":"elementor_theme","format":"standard","meta":{"content-type":"","inline_featured_image":false},"categories":[2497],"tags":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v21.7 (Yoast SEO v21.7) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Hello Daniel, qu\u2019est-ce que la normalisation des donn\u00e9es ?<\/title>\n<meta name=\"description\" content=\"Qu&#039;est ce que la normalisation des donn\u00e9es ? Daniel notre expert en data science qui r\u00e9pond aux questions de nos apprenants vous l&#039;explique !\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/datascientest.com\/normalisation-des-donnees\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Hello Daniel, qu\u2019est-ce que la normalisation des donn\u00e9es ?\" \/>\n<meta property=\"og:url\" content=\"https:\/\/datascientest.com\/normalisation-des-donnees\" \/>\n<meta property=\"og:site_name\" content=\"Formation Data Science | DataScientest.com\" \/>\n<meta property=\"article:published_time\" content=\"2020-12-29T13:56:13+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2023-11-09T14:11:15+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/12\/illu_normali_blog-49.png\" \/>\n\t<meta property=\"og:image:width\" content=\"4267\" \/>\n\t<meta property=\"og:image:height\" content=\"2342\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"author\" content=\"J\u00e9r\u00e9my Robert\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u00c9crit par\" \/>\n\t<meta name=\"twitter:data1\" content=\"J\u00e9r\u00e9my Robert\" \/>\n\t<meta name=\"twitter:label2\" content=\"Dur\u00e9e de lecture estim\u00e9e\" \/>\n\t<meta name=\"twitter:data2\" content=\"5 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/datascientest.com\/normalisation-des-donnees\",\"url\":\"https:\/\/datascientest.com\/normalisation-des-donnees\",\"name\":\"Hello Daniel, qu\u2019est-ce que la normalisation des donn\u00e9es ?\",\"isPartOf\":{\"@id\":\"https:\/\/datascientest.com\/#website\"},\"datePublished\":\"2020-12-29T13:56:13+00:00\",\"dateModified\":\"2023-11-09T14:11:15+00:00\",\"author\":{\"@id\":\"https:\/\/datascientest.com\/#\/schema\/person\/7af2361c48e24e79a8aa2360e6e74925\"},\"description\":\"Qu'est ce que la normalisation des donn\u00e9es ? 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