{"id":20712,"date":"2024-02-16T05:29:43","date_gmt":"2024-02-16T04:29:43","guid":{"rendered":"https:\/\/complex-systems-ai.com\/?page_id=20712"},"modified":"2024-02-16T06:04:30","modified_gmt":"2024-02-16T05:04:30","slug":"gini-entropie-et-erreur","status":"publish","type":"page","link":"https:\/\/complex-systems-ai.com\/es\/analisis-de-datos\/entropia-y-error-de-gini\/","title":{"rendered":"3 Medidas: impureza de Gini, entrop\u00eda y error de clasificaci\u00f3n"},"content":{"rendered":"<div data-elementor-type=\"wp-page\" data-elementor-id=\"20712\" class=\"elementor elementor-20712\">\n\t\t\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-19fdc32 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"19fdc32\" 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-b2d49fc\" data-id=\"b2d49fc\" 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-1ae617f elementor-align-justify elementor-widget elementor-widget-button\" data-id=\"1ae617f\" 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\/es\/analisis-de-datos\/\">\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\">An\u00e1lisis de datos<\/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-f96476a\" data-id=\"f96476a\" 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-7d1af2c elementor-align-justify elementor-widget elementor-widget-button\" data-id=\"7d1af2c\" 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\/es\/\">\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\">Pagina de inicio<\/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-6ec35d4\" data-id=\"6ec35d4\" 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-fa64005 elementor-align-justify elementor-widget elementor-widget-button\" data-id=\"fa64005\" 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:\/\/www.ibm.com\/docs\/fr\/cognos-analytics\/11.1.0?topic=terms-gini-impurity-measure\" 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-df700ef elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"df700ef\" 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-a986a05\" data-id=\"a986a05\" 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-4ad66dc elementor-widget elementor-widget-text-editor\" data-id=\"4ad66dc\" 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<p>La medida de impureza (Gini) implementa \u00e1rboles de decisi\u00f3n binarios y las tres medidas de impureza o criterios de divisi\u00f3n com\u00fanmente utilizados en los \u00e1rboles de decisi\u00f3n binarios son la impureza de Gini (IG), la entrop\u00eda (IH) y el error de clasificaci\u00f3n (IE).<\/p><p><img decoding=\"async\" class=\"aligncenter wp-image-11096 size-full\" src=\"http:\/\/complex-systems-ai.com\/wp-content\/uploads\/2020\/09\/cropped-Capture.png\" alt=\"gini\" width=\"97\" height=\"97\" title=\"\"><\/p>\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-091eb7d elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"091eb7d\" 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-cc8fab7\" data-id=\"cc8fab7\" 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-86f82fb elementor-widget elementor-widget-heading\" data-id=\"86f82fb\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_85 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\">Contenido<\/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=\"Tabla de contenido alternativo\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Palanca<\/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\/analisis-de-datos\/entropia-y-error-de-gini\/#Impurete-de-Gini\" >impureza de gini<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/complex-systems-ai.com\/es\/analisis-de-datos\/entropia-y-error-de-gini\/#Impurete-de-Gini-en-donnees-quantitatives\" >Impureza de Gini en datos cuantitativos.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/complex-systems-ai.com\/es\/analisis-de-datos\/entropia-y-error-de-gini\/#Impurete-de-Gini-en-donnees-qualitative\" >Impureza de Gini en datos cualitativos.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/complex-systems-ai.com\/es\/analisis-de-datos\/entropia-y-error-de-gini\/#Entropie\" >entrop\u00eda<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/complex-systems-ai.com\/es\/analisis-de-datos\/entropia-y-error-de-gini\/#Erreur-de-classification-Misclassification-impurity\" >Error de clasificaci\u00f3n\/impureza de clasificaci\u00f3n err\u00f3nea<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"elementor-heading-title elementor-size-default\"><span class=\"ez-toc-section\" id=\"Impurete-de-Gini\"><\/span>impureza de gini<span class=\"ez-toc-section-end\"><\/span><\/h2>\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-8755ab9 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"8755ab9\" 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-b89255e\" data-id=\"b89255e\" 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-a99afd8 elementor-widget elementor-widget-text-editor\" data-id=\"a99afd8\" 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<p>Utilizado por el algoritmo CART (<a href=\"https:\/\/complex-systems-ai.com\/es\/teoria-de-grafos\/arboles-y-arboles\/\">\u00e1rbol<\/a> clasificaci\u00f3n y <a href=\"https:\/\/complex-systems-ai.com\/es\/correlacion-y-regresiones\/\">regresi\u00f3n<\/a>) para los \u00e1rboles de clasificaci\u00f3n, la impureza de Gini es una medida de la frecuencia con la que un elemento del conjunto elegido al azar se etiquetar\u00eda incorrectamente si se etiquetara al azar en funci\u00f3n de la distribuci\u00f3n de etiquetas en el subconjunto.<\/p><p>Matem\u00e1ticamente, podemos escribir la impureza de Gini de la siguiente manera:<\/p><p><img decoding=\"async\" class=\"alignnone size-medium wp-image-20717\" src=\"http:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre6-300x70.webp\" alt=\"impureza de gini\" width=\"300\" height=\"70\" title=\"\" srcset=\"https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre6-300x70.webp 300w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre6-18x4.webp 18w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre6.webp 354w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p><p>donde j es el n\u00famero de clases presentes en el nodo y p es la distribuci\u00f3n de clases en el nodo.<\/p><p>Simulaci\u00f3n sencilla con un conjunto de datos de enfermedades card\u00edacas que consta de 303 filas y 13 atributos. El objetivo incluye 138 valores 0 y 165 valores 1.<\/p><p><img fetchpriority=\"high\" decoding=\"async\" class=\"alignnone wp-image-20718 size-full\" src=\"http:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre7.webp\" alt=\"impureza de gini\" width=\"505\" height=\"117\" title=\"\" srcset=\"https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre7.webp 505w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre7-300x70.webp 300w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre7-18x4.webp 18w\" sizes=\"(max-width: 505px) 100vw, 505px\" \/><\/p><p>Para crear un \u00e1rbol de decisi\u00f3n a partir del conjunto de datos y determinar qu\u00e9 separaci\u00f3n es mejor, necesitamos una forma de medir y comparar la impureza en cada atributo. El valor de impureza m\u00e1s bajo en la primera iteraci\u00f3n ser\u00e1 el nodo ra\u00edz. podemos escribir la ecuaci\u00f3n 3 en la forma:<\/p><p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-20720 size-full\" src=\"http:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre8.webp\" alt=\"impureza de gini\" width=\"720\" height=\"55\" title=\"\" srcset=\"https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre8.webp 720w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre8-300x23.webp 300w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre8-18x1.webp 18w\" sizes=\"(max-width: 720px) 100vw, 720px\" \/><\/p><p>En esta simulaci\u00f3n, utilice s\u00f3lo el sexo, fbs (glucosa en sangre en ayunas), exang (angina inducida por el ejercicio) y atributos objetivo.<\/p><p>C\u00f3mo medir la impureza en el atributo Sexo:<\/p><p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-20721 size-full\" src=\"http:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre9.webp\" alt=\"impureza de gini\" width=\"523\" height=\"301\" title=\"\" srcset=\"https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre9.webp 523w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre9-300x173.webp 300w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre9-18x10.webp 18w\" sizes=\"(max-width: 523px) 100vw, 523px\" \/><\/p><ul><li>Nudo izquierdo = 0,29<\/li><li>Nudo derecho = 0,49<\/li><\/ul><p>Ahora que hemos medido la impureza de ambos nodos de las hojas. Podemos calcular la impureza total con el promedio en peso. El ganglio izquierdo represent\u00f3 138 pacientes mientras que el derecho represent\u00f3 165 pacientes.<\/p><p>Impureza total de Gini \u2014 Nodo hoja<\/p><p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-20722 size-full\" src=\"http:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre10.webp\" alt=\"impureza de gini\" width=\"496\" height=\"252\" title=\"\" srcset=\"https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre10.webp 496w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre10-300x152.webp 300w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre10-18x9.webp 18w\" sizes=\"(max-width: 496px) 100vw, 496px\" \/><\/p><p>Procedemos de la misma manera con el resto de atributos:<\/p><ul><li>I_fbs_izquierda = 0,268; derecha = 0,234; I_fbs = 0,249<\/li><li>I_exang_left =0,596; derecha = 0,234; I_Exang = 0,399<\/li><\/ul><p>Fbs (az\u00facar en sangre en ayunas) tiene la impureza de Gini m\u00e1s baja, as\u00ed que \u00faselo en el nodo ra\u00edz.<\/p>\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-d420e28 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"d420e28\" 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-c970856\" data-id=\"c970856\" 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-06f5ecb elementor-widget elementor-widget-heading\" data-id=\"06f5ecb\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\"><span class=\"ez-toc-section\" id=\"Impurete-de-Gini-en-donnees-quantitatives\"><\/span>Impureza de Gini en datos cuantitativos.<span class=\"ez-toc-section-end\"><\/span><\/h2>\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-5585556 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"5585556\" 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-ed01d91\" data-id=\"ed01d91\" 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-c071cd4 elementor-widget elementor-widget-text-editor\" data-id=\"c071cd4\" 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<p>Como el peso que es uno de los atributos para determinar enfermedades card\u00edacas, por ejemplo tenemos el atributo peso:<\/p><p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-20723\" src=\"http:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre11-300x291.webp\" alt=\"Gini cuantitativo\" width=\"300\" height=\"291\" title=\"\" srcset=\"https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre11-300x291.webp 300w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre11-12x12.webp 12w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre11.webp 321w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p><p>Despu\u00e9s de ordenar en orden ascendente, haga el promedio par consecutivo y calcule la impureza para cada valor.<\/p><p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-20724 size-large\" src=\"http:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre12-1024x292.webp\" alt=\"gini cuantitativo\" width=\"1024\" height=\"292\" title=\"\" srcset=\"https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre12-1024x292.webp 1024w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre12-300x86.webp 300w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre12-768x219.webp 768w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre12-18x5.webp 18w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre12.webp 1100w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/p><p>La impureza de Gini m\u00e1s baja es el peso &lt;205, este es el valor umbral y el valor de impureza si se usa cuando lo comparamos con otro atributo.<\/p><p>Por motivos de c\u00e1lculo, tambi\u00e9n es posible hacerlo por cuantiles.<\/p>\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-a5ebb91 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"a5ebb91\" 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-4e377d6\" data-id=\"4e377d6\" 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-f83c587 elementor-widget elementor-widget-heading\" data-id=\"f83c587\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\"><span class=\"ez-toc-section\" id=\"Impurete-de-Gini-en-donnees-qualitative\"><\/span>Impureza de Gini en datos cualitativos.<span class=\"ez-toc-section-end\"><\/span><\/h2>\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-cd4c493 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"cd4c493\" 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-3d3c0eb\" data-id=\"3d3c0eb\" 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-8ffcdbd elementor-widget elementor-widget-text-editor\" data-id=\"8ffcdbd\" 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<p>Tenemos un atributo de color preferido para determinar el g\u00e9nero de una persona:<\/p><p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-20725\" src=\"http:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre13-289x300.webp\" alt=\"gini cualitativo\" width=\"289\" height=\"300\" title=\"\" srcset=\"https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre13-289x300.webp 289w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre13-12x12.webp 12w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre13.webp 300w\" sizes=\"(max-width: 289px) 100vw, 289px\" \/><\/p><p>Para saber qu\u00e9 tan impureza es este atributo, calcule una puntuaci\u00f3n de impureza para cada uno (como un valor booleano), as\u00ed como para cada combinaci\u00f3n posible.<\/p>\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-7592831 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"7592831\" 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-b681c38\" data-id=\"b681c38\" 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-957768c elementor-widget elementor-widget-heading\" data-id=\"957768c\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\"><span class=\"ez-toc-section\" id=\"Entropie\"><\/span>entrop\u00eda<span class=\"ez-toc-section-end\"><\/span><\/h2>\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-7eb9e4e elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"7eb9e4e\" 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-0d130dd\" data-id=\"0d130dd\" 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-fc49e52 elementor-widget elementor-widget-text-editor\" data-id=\"fc49e52\" 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<p>Utilizado por los algoritmos de generaci\u00f3n de \u00e1rboles ID3, C4.5 y C5.0. La ganancia de informaci\u00f3n se basa en la noci\u00f3n de entrop\u00eda, la medida de entrop\u00eda se define como:<\/p><p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-20726\" src=\"http:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre14-300x70.webp\" alt=\"entrop\u00eda\" width=\"300\" height=\"70\" title=\"\" srcset=\"https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre14-300x70.webp 300w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre14-18x4.webp 18w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre14.webp 315w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p><p>donde j es el n\u00famero de clases presentes en el nodo y p es la distribuci\u00f3n de clases en el nodo.<\/p><p>Dado el mismo caso y conjunto de datos, necesitamos una forma de medir y comparar la entrop\u00eda en cada atributo. El valor de entrop\u00eda m\u00e1s alto en la primera iteraci\u00f3n ser\u00e1 el nodo ra\u00edz.<\/p><p>Primero necesitamos calcular la entrop\u00eda en el atributo Target = 0,994.<\/p><p>Usamos la misma divisi\u00f3n para el sexo:\u00a0<\/p><ul><li>sexo = 0 tiene para la entrop\u00eda 0,666<\/li><li>sexo = 1 tiene entrop\u00eda 0.988<\/li><\/ul><p>Ahora que hemos medido la entrop\u00eda de los dos nodos hoja. Tomamos el promedio de los pesos para calcular el valor de entrop\u00eda total.<\/p><p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-20727 size-full\" src=\"http:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre15.webp\" alt=\"\u00e1rbol de decisi\u00f3n de entrop\u00eda\" width=\"720\" height=\"282\" title=\"\" srcset=\"https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre15.webp 720w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre15-300x118.webp 300w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre15-18x7.webp 18w\" sizes=\"(max-width: 720px) 100vw, 720px\" \/><\/p><p>Entrop\u00eda para la columna Fbs = 0,389<\/p><p>Entrop\u00eda para la columna Exang = 0,224<\/p><p>Fbs (az\u00facar en sangre en ayunas) tiene la entrop\u00eda m\u00e1s alta, por lo que lo usaremos en el nodo ra\u00edz, exactamente los mismos resultados que obtuvimos con la impureza de Gini.<\/p>\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-b8a58b8 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"b8a58b8\" 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-d67829e\" data-id=\"d67829e\" 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-435e5a8 elementor-widget elementor-widget-heading\" data-id=\"435e5a8\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\"><span class=\"ez-toc-section\" id=\"Erreur-de-classification-Misclassification-impurity\"><\/span>Error de clasificaci\u00f3n\/impureza de clasificaci\u00f3n err\u00f3nea<span class=\"ez-toc-section-end\"><\/span><\/h2>\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-6b89df7 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"6b89df7\" 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-4836bd6\" data-id=\"4836bd6\" 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-5bafb57 elementor-widget elementor-widget-text-editor\" data-id=\"5bafb57\" 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<p>Otra medida de impureza es la impureza por clasificaci\u00f3n err\u00f3nea o error de clasificaci\u00f3n err\u00f3nea. Matem\u00e1ticamente, podemos escribir la impureza de clasificaci\u00f3n err\u00f3nea de la siguiente manera:<\/p><p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-20728\" src=\"http:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre16-300x65.webp\" alt=\"impureza de clasificaci\u00f3n\" width=\"300\" height=\"65\" title=\"\" srcset=\"https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre16-300x65.webp 300w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre16-18x4.webp 18w, https:\/\/complex-systems-ai.com\/wp-content\/uploads\/2024\/02\/arbre16.webp 348w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p><p>En t\u00e9rminos de desempe\u00f1o cualitativo, este \u00edndice no es la mejor opci\u00f3n porque no es particularmente sensible a diferentes distribuciones de probabilidad (que pueden f\u00e1cilmente llevar la selecci\u00f3n hacia la subdivisi\u00f3n usando Gini o entrop\u00eda).<\/p>\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>","protected":false},"excerpt":{"rendered":"<p>P\u00e1gina de inicio de an\u00e1lisis de datos Wiki La medida de impureza (Gini) implementa \u00e1rboles de decisi\u00f3n binarios y las tres medidas o criterios de impureza de\u2026 <\/p>","protected":false},"author":1,"featured_media":0,"parent":15503,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-20712","page","type-page","status-publish","hentry"],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/complex-systems-ai.com\/es\/wp-json\/wp\/v2\/pages\/20712","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=20712"}],"version-history":[{"count":4,"href":"https:\/\/complex-systems-ai.com\/es\/wp-json\/wp\/v2\/pages\/20712\/revisions"}],"predecessor-version":[{"id":20731,"href":"https:\/\/complex-systems-ai.com\/es\/wp-json\/wp\/v2\/pages\/20712\/revisions\/20731"}],"up":[{"embeddable":true,"href":"https:\/\/complex-systems-ai.com\/es\/wp-json\/wp\/v2\/pages\/15503"}],"wp:attachment":[{"href":"https:\/\/complex-systems-ai.com\/es\/wp-json\/wp\/v2\/media?parent=20712"}],"curies":[{"name":"gracias","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}