{"id":19104,"date":"2020-11-19T16:46:51","date_gmt":"2020-11-19T16:46:51","guid":{"rendered":"https:\/\/datascientest.com\/?p=19104"},"modified":"2023-11-09T14:11:32","modified_gmt":"2023-11-09T14:11:32","slug":"knn","status":"publish","type":"post","link":"https:\/\/datascientest.com\/knn","title":{"rendered":"Qu\u2019est ce que l\u2019algorithme KNN ?"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"19104\" class=\"elementor elementor-19104\" data-elementor-post-type=\"post\">\n\t\t\t\t\t\t\t<div class=\"elementor-element elementor-element-54e51c4 e-flex e-con-boxed e-con\" data-id=\"54e51c4\" 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-73610ae elementor-widget elementor-widget-heading\" data-id=\"73610ae\" 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\">L\u2019algorithme des K plus proches voisins ou K-nearest neighbors (kNN) est un algorithme de Machine Learning qui appartient \u00e0 la classe des algorithmes d\u2019apprentissage supervis\u00e9 simple et facile \u00e0 mettre en \u0153uvre qui peut \u00eatre utilis\u00e9 pour r\u00e9soudre les probl\u00e8mes de classification et de r\u00e9gression. Dans cet article, nous allons revenir sur la d\u00e9finition de cet algorithme, son fonctionnement ainsi qu\u2019une application directe en programmation.<\/h2>\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-d39ff71 e-flex e-con-boxed e-con\" data-id=\"d39ff71\" 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-ec92592 elementor-widget elementor-widget-heading\" data-id=\"ec92592\" 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\">KNN : D\u00e9finition<\/h3>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-96233f3 elementor-widget elementor-widget-text-editor\" data-id=\"96233f3\" 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>Avant de nous concentrer sur<strong> l\u2019algorithme KNN<\/strong>, il est n\u00e9cessaire de reprendre les bases.\u00a0 Qu\u2019est-ce qu\u2019un algorithme d\u2019apprentissage supervis\u00e9?\u00a0<\/p><p>En <a href=\"https:\/\/datascientest.com\/apprentissage-supervise\">apprentissage supervis\u00e9<\/a>, un algorithme re\u00e7oit un ensemble de donn\u00e9es qui est \u00e9tiquet\u00e9 avec des valeurs de sorties correspondantes sur lequel il va pouvoir s&rsquo;entra\u00eener et d\u00e9finir un mod\u00e8le de pr\u00e9diction. Cet algorithme pourra par la suite \u00eatre utilis\u00e9 sur de nouvelles donn\u00e9es afin de pr\u00e9dire leurs valeurs de sorties correspondantes.<\/p><p>Voici une illustration simplifi\u00e9e :<\/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-34c1d5a elementor-widget elementor-widget-image\" data-id=\"34c1d5a\" 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=\"2291\" height=\"1564\" src=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-1-KNN.jpg\" class=\"attachment-full size-full wp-image-19106\" alt=\"knn\" srcset=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-1-KNN.jpg 2291w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-1-KNN-300x205.jpg 300w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-1-KNN-1024x699.jpg 1024w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-1-KNN-768x524.jpg 768w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-1-KNN-1536x1049.jpg 1536w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-1-KNN-2048x1398.jpg 2048w\" sizes=\"(max-width: 2291px) 100vw, 2291px\" \/>\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-286efb9 elementor-widget elementor-widget-text-editor\" data-id=\"286efb9\" 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>L&rsquo;intuition derri\u00e8re <strong>l&rsquo;algorithme des K<\/strong> plus proches voisins est l&rsquo;une des plus simples de tous les algorithmes de Machine Learning supervis\u00e9\u00a0:<\/p><ul><li><strong>\u00c9tape 1 :<\/strong>\u00a0 S\u00e9lectionnez le nombre K de voisins<\/li><li><strong>\u00c9tape 2 :<\/strong>\u00a0 Calculez la distance<\/li><\/ul>\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-f83ccb4 e-flex e-con-boxed e-con\" data-id=\"f83ccb4\" 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<div class=\"elementor-element elementor-element-130a04a e-con-full e-flex e-con\" data-id=\"130a04a\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;full&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-14c3f4f elementor-widget elementor-widget-image\" data-id=\"14c3f4f\" 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<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"363\" height=\"179\" src=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/eucledienne.png\" class=\"attachment-large size-large wp-image-19109\" alt=\"eucledienne\" srcset=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/eucledienne.png 363w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/eucledienne-300x148.png 300w\" sizes=\"(max-width: 363px) 100vw, 363px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Manhattan<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-94c36ef e-con-full e-flex e-con\" data-id=\"94c36ef\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;full&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-8b13b74 elementor-widget elementor-widget-image\" data-id=\"8b13b74\" 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<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"471\" height=\"179\" src=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/m.png\" class=\"attachment-large size-large wp-image-19114\" alt=\"Manhattan\" srcset=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/m.png 471w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/m-300x114.png 300w\" sizes=\"(max-width: 471px) 100vw, 471px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Euclidienne  <\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\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-a9c00ee e-flex e-con-boxed e-con\" data-id=\"a9c00ee\" 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-15a85b9 elementor-widget elementor-widget-text-editor\" data-id=\"15a85b9\" 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>Du point non classifi\u00e9 aux autres points.<\/p><ul><li><strong>\u00c9tape 3<\/strong> :\u00a0 Prenez les K voisins les plus proches selon la distance calcul\u00e9e.<\/li><li><strong>\u00c9tape 4<\/strong> :\u00a0 Parmi ces K voisins, comptez le nombre de points\u00a0 appartenant \u00e0 chaque cat\u00e9gorie.<\/li><li><strong>\u00c9tape 5<\/strong> : Attribuez le nouveau point \u00e0 la cat\u00e9gorie la plus pr\u00e9sente parmis ces K voisins.<\/li><li><strong>\u00c9tape 6<\/strong> : Notre mod\u00e8le est pr\u00eat\u00a0:<\/li><\/ul>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-dc27d83 elementor-widget elementor-widget-image\" data-id=\"dc27d83\" 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=\"2385\" height=\"1145\" src=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-2-KNN.jpg\" class=\"attachment-full size-full wp-image-19131\" alt=\"knn\" srcset=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-2-KNN.jpg 2385w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-2-KNN-300x144.jpg 300w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-2-KNN-1024x492.jpg 1024w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-2-KNN-768x369.jpg 768w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-2-KNN-1536x737.jpg 1536w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-2-KNN-2048x983.jpg 2048w\" sizes=\"(max-width: 2385px) 100vw, 2385px\" \/>\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-b144be4 elementor-align-center button-principale elementor-widget elementor-widget-button\" data-id=\"b144be4\" 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 l'algorithme KNN<\/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-360af17 e-flex e-con-boxed e-con\" data-id=\"360af17\" 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-dca024e elementor-widget elementor-widget-heading\" data-id=\"dca024e\" 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\">KNN : Exemple d\u2019utilisation <\/h3>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-76639c7 elementor-widget elementor-widget-text-editor\" data-id=\"76639c7\" 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>Nous pouvons \u00e0 pr\u00e9sent nous int\u00e9resser \u00e0 un exemple d\u2019utilisation de l\u2019algorithme des K plus proches voisins. Gr\u00e2ce \u00e0 la librairie <a href=\"https:\/\/datascientest.com\/tout-savoir-sur-scikit-learn\">Scikit-Learn<\/a>, nous pouvons importer la fonction <strong>KKNeighborsClassifier<\/strong> que nous utiliserons sur le jeu de donn\u00e9e IRIS.<\/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-e8afe83 elementor-widget elementor-widget-image\" data-id=\"e8afe83\" 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=\"2530\" height=\"772\" src=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-3-KNN.jpg\" class=\"attachment-full size-full wp-image-19160\" alt=\"Knn\" srcset=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-3-KNN.jpg 2530w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-3-KNN-300x92.jpg 300w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-3-KNN-1024x312.jpg 1024w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-3-KNN-768x234.jpg 768w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-3-KNN-1536x469.jpg 1536w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-3-KNN-2048x625.jpg 2048w\" sizes=\"(max-width: 2530px) 100vw, 2530px\" \/>\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-1198fc8 elementor-widget elementor-widget-text-editor\" data-id=\"1198fc8\" 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>Gr\u00e2ce \u00e0 l\u2019algorithme KNN, nous obtenons un excellent taux de bonne classification des plantes proches des 100%. On peut \u00e9galement s\u2019int\u00e9resser \u00e0 un moyen de <strong>choisir le K pour lequel la classification sera la meilleure.<\/strong> Une fa\u00e7on de le trouver consiste \u00e0 tracer le graphique de la valeur K et le taux d&rsquo;erreur correspondant pour l&rsquo;ensemble de donn\u00e9es\u00a0:\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-b036baa elementor-widget elementor-widget-image\" data-id=\"b036baa\" 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=\"2319\" height=\"1293\" src=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-4-KNN.jpg\" class=\"attachment-full size-full wp-image-19161\" alt=\"knn\" srcset=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-4-KNN.jpg 2319w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-4-KNN-300x167.jpg 300w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-4-KNN-1024x571.jpg 1024w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-4-KNN-768x428.jpg 768w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-4-KNN-1536x856.jpg 1536w, https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/Illu-4-KNN-2048x1142.jpg 2048w\" sizes=\"(max-width: 2319px) 100vw, 2319px\" \/>\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-d90bc9f elementor-widget elementor-widget-text-editor\" data-id=\"d90bc9f\" 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>Ainsi, nous pouvons voir que le meilleur taux de pr\u00e9diction est obtenu pour un K entre 5\u00a0et 18. Au-dessus de cette valeur, on peut observer un ph\u00e9nom\u00e8ne nomm\u00e9 \u00ab\u00a0Overfitting\u00a0\u00bb ou Sur apprentissage en Fran\u00e7ais qui se produit lorsque les donn\u00e9es d\u2019apprentissage utilis\u00e9es pour construire un mod\u00e8le expliquent tr\u00e8s voire \u00ab\u00a0trop\u00a0\u00bb bien les donn\u00e9es mais ne parviennent pas \u00e0 faire des pr\u00e9dictions utiles pour de nouvelles donn\u00e9es.<\/p><p>Quelques applications :<\/p><ul><li>Il peut \u00eatre utilis\u00e9 dans des <strong>technologies comme l&rsquo;OCR (Optical Character Recognizer)<\/strong>, qui tente de d\u00e9tecter l&rsquo;\u00e9criture manuscrite, les images et m\u00eame les vid\u00e9os.<\/li><li>Il peut \u00eatre utilis\u00e9 dans le domaine des <strong>notations de cr\u00e9dit<\/strong>. Il essaie de faire correspondre les caract\u00e9ristiques d&rsquo;un individu avec le groupe de personnes existantes afin de lui attribuer la cote de cr\u00e9dit. Il se verra attribuer <strong>la m\u00eame note que celle accord\u00e9e aux personnes correspondant \u00e0 ses caract\u00e9ristiques<\/strong>.<\/li><li>Il est utilis\u00e9 pour <strong>pr\u00e9dire si la banque doit accorder un pr\u00eat \u00e0 un particulier<\/strong>. Il tentera d&rsquo;\u00e9valuer si l&rsquo;individu donn\u00e9 correspond aux crit\u00e8res des personnes qui avaient pr\u00e9c\u00e9demment fait d\u00e9faut ou ne fera pas d\u00e9faut \u00e0 son pr\u00eat.<\/li><\/ul>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-3a49d88 elementor-widget elementor-widget-text-editor\" data-id=\"3a49d88\" 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>Avantages\u00a0:<\/p><ul><li>L&rsquo;algorithme est <strong>simple et facile \u00e0 mettre en \u0153uvre<\/strong>.<br \/>Il n&rsquo;est pas n\u00e9cessaire de cr\u00e9er un mod\u00e8le, de r\u00e9gler plusieurs param\u00e8tres ou de formuler des hypoth\u00e8ses suppl\u00e9mentaires.<\/li><li>L&rsquo;algorithme est polyvalent. Il peut \u00eatre utilis\u00e9 pour la <strong>classification<\/strong> ou la <strong>r\u00e9gression<\/strong>.<\/li><\/ul>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-5b1f095 elementor-widget elementor-widget-text-editor\" data-id=\"5b1f095\" 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>Inconv\u00e9nients\u00a0:<\/p><ul><li>L&rsquo;algorithme devient beaucoup plus lent \u00e0 mesure que le nombre d&rsquo;observation et de variables ind\u00e9pendantes augmente.<\/li><\/ul>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-9d5e75c elementor-widget elementor-widget-text-editor\" data-id=\"9d5e75c\" 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>\u00c9tant l&rsquo;un des algorithmes les plus simples de <a href=\"https:\/\/datascientest.com\/apprentissage-automatique\">Machine Learning<\/a>, il est hautement impl\u00e9ment\u00e9 pour d\u00e9velopper des syst\u00e8mes bas\u00e9s sur l&rsquo;apprentissage, intuitifs et intelligents qui pourraient effectuer et prendre de petites d\u00e9cisions tout seuls.<\/p><p>Cela rend les choses encore plus pratiques pour l&rsquo;apprentissage et le d\u00e9veloppement et aide presque tous les types d&rsquo;industries qui pourraient utiliser des syst\u00e8mes, des solutions ou des services intelligents.\u00a0<\/p><p>Il existe pleins d\u2019autres algorithmes de <strong>Clustering<\/strong> supervis\u00e9 ou non Supervis\u00e9 qui seront plus ou moins appropri\u00e9 selon la situation comme celui des <a href=\"https:\/\/datascientest.com\/algorithme-des-k-means\">K-means<\/a>, du <a href=\"https:\/\/datascientest.com\/machine-learning-clustering-focus-sur-algorithme-cah\">CAH<\/a> (La classification ascendante hi\u00e9rarchique ), <a href=\"https:\/\/datascientest.com\/machine-learning-clustering-dbscan\">DBSCAN<\/a> (density-based spatial clustering of applications with noise)\u2026 que vous pouvez retrouver sur notre <a href=\"https:\/\/datascientest.com\/blog-data-ia-actualites\">blog<\/a>.<\/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-4c0ee34 elementor-align-center button-principale elementor-widget elementor-widget-button\" data-id=\"4c0ee34\" 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\">D\u00e9couvrir nos formations<\/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>L\u2019algorithme des K plus proches voisins ou K-nearest neighbors (kNN) est un algorithme de Machine Learning qui appartient \u00e0 la classe des algorithmes d\u2019apprentissage supervis\u00e9 simple et facile \u00e0 mettre en \u0153uvre qui peut \u00eatre utilis\u00e9 pour r\u00e9soudre les probl\u00e8mes de classification et de r\u00e9gression. Dans cet article, nous allons revenir sur la d\u00e9finition de [&hellip;]<\/p>\n","protected":false},"author":78,"featured_media":19657,"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>KNN : D\u00e9couvrez cet algorithme de Machine Learning<\/title>\n<meta name=\"description\" content=\"D\u00e9couvrez l&#039;algorithme KNN: un algorithme en apprentissage supervis\u00e9 populaire en Clustering discipline essentielle du Machine Learning.\" \/>\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\/knn\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Qu\u2019est ce que l\u2019algorithme KNN ?\" \/>\n<meta property=\"og:url\" content=\"https:\/\/datascientest.com\/knn\" \/>\n<meta property=\"og:site_name\" content=\"Formation Data Science | DataScientest.com\" \/>\n<meta property=\"article:published_time\" content=\"2020-11-19T16:46:51+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2023-11-09T14:11:32+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/datascientest.com\/wp-content\/uploads\/2020\/11\/illu_KNN_blog-23.png\" \/>\n\t<meta property=\"og:image:width\" content=\"4268\" \/>\n\t<meta property=\"og:image:height\" content=\"2343\" \/>\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\/knn\",\"url\":\"https:\/\/datascientest.com\/knn\",\"name\":\"KNN : D\u00e9couvrez cet algorithme de Machine Learning\",\"isPartOf\":{\"@id\":\"https:\/\/datascientest.com\/#website\"},\"datePublished\":\"2020-11-19T16:46:51+00:00\",\"dateModified\":\"2023-11-09T14:11:32+00:00\",\"author\":{\"@id\":\"https:\/\/datascientest.com\/#\/schema\/person\/7af2361c48e24e79a8aa2360e6e74925\"},\"description\":\"D\u00e9couvrez l'algorithme KNN: un algorithme en apprentissage supervis\u00e9 populaire en Clustering discipline essentielle du Machine Learning.\",\"inLanguage\":\"fr-FR\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/datascientest.com\/knn\"]}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/datascientest.com\/#website\",\"url\":\"https:\/\/datascientest.com\/\",\"name\":\"Formation Data Science | DataScientest.com\",\"description\":\"Leader de la formation en Data Science\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/datascientest.com\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"fr-FR\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/datascientest.com\/#\/schema\/person\/7af2361c48e24e79a8aa2360e6e74925\",\"name\":\"J\u00e9r\u00e9my Robert\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"fr-FR\",\"@id\":\"https:\/\/datascientest.com\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/datascientest.com\/wp-content\/uploads\/2023\/11\/jeremyrobert.jpeg\",\"contentUrl\":\"https:\/\/datascientest.com\/wp-content\/uploads\/2023\/11\/jeremyrobert.jpeg\",\"caption\":\"J\u00e9r\u00e9my Robert\"},\"description\":\"J\u00e9r\u00e9my Robert est actuellement Directeur p\u00e9dagogique B2B chez DataScientest.com. 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