{"id":138,"date":"2025-12-05T17:56:46","date_gmt":"2025-12-05T23:56:46","guid":{"rendered":"https:\/\/dcsh.izt.uam.mx\/proyectos\/s\/?page_id=138"},"modified":"2026-05-27T06:38:25","modified_gmt":"2026-05-27T12:38:25","slug":"base-de-datos-auto","status":"publish","type":"page","link":"https:\/\/dcsh.izt.uam.mx\/proyectos\/s\/?page_id=138","title":{"rendered":"Base de datos auto"},"content":{"rendered":"<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>Tablas de frecuencia con condicionales:\u00a0 tabulate<\/p>\n<p>Las tablas de frecuencia absoluta nos permiten contabilizar casos que cumplen con determinadas condiciones, Stata genera este tipo de tablas mediante diversas formas, una de ella es mediante el comando tabulate, en el mismo, tal como muestran los siguientes ejemplos, podemos adem\u00e1s introducir filtros, condicionales, factores de expansi\u00f3n y las dem\u00e1s bondades de Stata .<\/p>\n<p>* Tabla de frecuencia absoluta, relativa y relativa acumulada<\/p>\n<p>. tabulate foreign<\/p>\n<p>Car type | Freq. Percent Cum.<br \/>\n&#8212;&#8212;&#8212;&#8212;+&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;<br \/>\nDomestic | 52 70.27 70.27<br \/>\nForeign | 22 29.73 100.00<br \/>\n&#8212;&#8212;&#8212;&#8212;+&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;<br \/>\nTotal | 74 100.00<\/p>\n<p>Especific\u00e1ndole dos variables, tambi\u00e9n podemos obtener una tabla de contingencia cruzada:<\/p>\n<p>. tabulate mpg foreign<\/p>\n<p>Mileage | Car type<br \/>\n(mpg) | Domestic Foreign | Total<br \/>\n&#8212;&#8212;&#8212;&#8211;+&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;-+&#8212;&#8212;&#8212;-<br \/>\n12 | 2 0 | 2<br \/>\n14 | 5 1 | 6<br \/>\n15 | 2 0 | 2<br \/>\n16 | 4 0 | 4<br \/>\n17 | 2 2 | 4<br \/>\n&#8230;<br \/>\n41 | 0 1 | 1<br \/>\n&#8212;&#8212;&#8212;&#8211;+&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;-+&#8212;&#8212;&#8212;-<br \/>\nTotal | 52 22 | 74<\/p>\n<p>Tambi\u00e9n podemos introducir filtros o condicionales a nuestras tablas, esto resulta interesante cuando deseamos restringir nuestro an\u00e1lisis a solo un grupo especial de la poblaci\u00f3n. El pr\u00f3ximo comando muestra la tabla de frecuencias de las variables s\u00f3lo para las observaciones que cumplen la expresi\u00f3n especificada despu\u00e9s del if.<\/p>\n<p>Tablas de estad\u00edsticos descriptivos<\/p>\n<p>Los estad\u00edsticos descriptivos constituyen una de las primeras miradas brindada a nuestra base de datos, Utilizando las especificaciones de contenido, se obtiene la tabla, conteniendo la deviaci\u00f3n y la media de los precios seg\u00fan el origen de producci\u00f3n de los coches.<\/p>\n<p>. table foreign, contents (n price mean price sd price )<\/p>\n<p>&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;-<br \/>\nCar type | N(price) mean(price) sd(price)<br \/>\n&#8212;&#8212;&#8212;-+&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;<br \/>\nDomestic | 52 6,072.4 3097.104<br \/>\nForeign | 22 6,384.7 2621.915<br \/>\n&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;-<\/p>\n<p>\u201cA\u00f1adiendo adem\u00e1s la opci\u00f3n row (col), la tabla incluir\u00e1 una fila (columna) adicional con los valores totales, para cada valor de las opciones que aparecen\u201d.<\/p>\n<p>table foreign, contents (n price mean price sd price ) row<\/p>\n<p>&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;-<br \/>\nCar type | N(price) mean(price) sd(price)<br \/>\n&#8212;&#8212;&#8212;-+&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;<br \/>\nDomestic | 52 6,072.4 3097.104<br \/>\nForeign | 22 6,384.7 2621.915<br \/>\n|<br \/>\nTotal | 74 6,165.3 2949.496<\/p>\n<p>Podemos tambi\u00e9n solicitar as estad\u00edsticas para diversas variables, pero tambi\u00e9n podemos obtener muchos otros estad\u00edsticos descriptivos (Gresia, 2012), como por ejemplo:<\/p>\n<p>tabstat price length weight if foreign == 1, s(count min max mean sd cv sk p50 p50 p75 p90)<\/p>\n<p>stats | price length weight<br \/>\n&#8212;&#8212;&#8212;+&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;<br \/>\nN | 22 22 22<br \/>\nmin | 3748 142 1760<br \/>\nmax | 12990 193 3420<br \/>\nmean | 6384.682 168.5455 2315.909<br \/>\nsd | 2621.915 13.68255 433.0035<br \/>\ncv | .4106571 .0811802 .1869691<br \/>\nskewness | 1.215236 .0809646 1.056582<br \/>\np50 | 5759 170 2180<br \/>\np50 | 5759 170 2180<br \/>\np75 | 7140 175 2650<br \/>\np90 | 9735 189 2830<br \/>\n&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;-<\/p>\n<p>Tambi\u00e9n, se puede combinar summ con el comando tabulate para obtener un resumen de estad\u00edstico descriptivo de alguna variables seg\u00fan condiciones espec\u00edficas.<\/p>\n<p>tabulate foreign, summarize( price)<\/p>\n<p>| Summary of Price<br \/>\nCar type | Mean Std. Dev. Freq.<br \/>\n&#8212;&#8212;&#8212;&#8212;+&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;<br \/>\nDomestic | 6,072.423 3,097.104 52<br \/>\nForeign | 6,384.682 2,621.915 22<br \/>\n&#8212;&#8212;&#8212;&#8212;+&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;<br \/>\nTotal | 6,165.257 2,949.496 74<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&nbsp; &nbsp; Tablas de frecuencia con condicionales:\u00a0 tabulate Las tablas de frecuencia absoluta nos permiten contabilizar casos que cumplen con determinadas condiciones, Stata genera este tipo de tablas mediante diversas formas, una de ella es mediante el comando tabulate, en &hellip; <a href=\"https:\/\/dcsh.izt.uam.mx\/proyectos\/s\/?page_id=138\">Sigue leyendo <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-138","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/dcsh.izt.uam.mx\/proyectos\/s\/index.php?rest_route=\/wp\/v2\/pages\/138","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dcsh.izt.uam.mx\/proyectos\/s\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/dcsh.izt.uam.mx\/proyectos\/s\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/dcsh.izt.uam.mx\/proyectos\/s\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dcsh.izt.uam.mx\/proyectos\/s\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=138"}],"version-history":[{"count":7,"href":"https:\/\/dcsh.izt.uam.mx\/proyectos\/s\/index.php?rest_route=\/wp\/v2\/pages\/138\/revisions"}],"predecessor-version":[{"id":248,"href":"https:\/\/dcsh.izt.uam.mx\/proyectos\/s\/index.php?rest_route=\/wp\/v2\/pages\/138\/revisions\/248"}],"wp:attachment":[{"href":"https:\/\/dcsh.izt.uam.mx\/proyectos\/s\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=138"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}