{"id":2631,"date":"2023-07-21T10:30:26","date_gmt":"2023-07-21T10:30:26","guid":{"rendered":"https:\/\/statorials.org\/it\/sas-percentili\/"},"modified":"2023-07-21T10:30:26","modified_gmt":"2023-07-21T10:30:26","slug":"sas-percentili","status":"publish","type":"post","link":"https:\/\/statorials.org\/it\/sas-percentili\/","title":{"rendered":"Come calcolare i percentili in sas: con esempi"},"content":{"rendered":"

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Ecco i tre modi pi\u00f9 comuni per calcolare i percentili per un set di dati in SAS:<\/span><\/p>\n

Metodo 1: calcolare un valore percentile specifico<\/strong><\/span><\/p>\n

 \/*calculate 70th percentile value for var1*\/\n<\/span>proc univariate<\/span> data<\/span> =original_data;\n    <\/span>var<\/span> var1;\n    <\/span>output out<\/span> =percentile_data\n<\/span>pctlpts<\/span> =<\/span> 70<\/span>\n    pctlpre<\/span> = P_;\n<\/span>run<\/span> ;\n<\/span><\/strong><\/span><\/pre>\n
 Metodo 2: calcolare pi\u00f9 valori percentili specifici<\/strong><\/span><\/p>\n
 \/*calculate 70th, 80th, and 90th percentile value for var1*\/\n<\/span>proc univariate<\/span> data<\/span> =original_data;\n    var<\/span> var1;\n    output out<\/span> =percentile_data\n    pctlpts<\/span> = 70 80 90<\/span>\n    pctlpre<\/span> = P_;\nrun<\/span> ;<\/strong><\/span><\/pre>\n
 Metodo 3: calcolare i percentili per gruppo<\/strong><\/span><\/p>\n
 \/*sort original data by var2*\/\n<\/span>proc sort<\/span> data<\/span> = original_data;\n    by<\/span> var2;\nrun<\/span> ;\n\n\/*calculate percentiles for var1 grouped by var2*\/\n<\/span>proc univariate<\/span> data<\/span> =original_data;\n    var<\/span> var1;\n    by<\/span> var2;\n    output<\/span> out<\/span> =percentile_data\n    pctlpts<\/span> = 70, 80, 90\n    pctlpre<\/span> = P_;\nrun<\/span> ;<\/strong><\/span><\/pre>\n
 Nota<\/strong> : l’istruzione pctlpts<\/strong> specifica i percentili da calcolare e l’istruzione pctlpre<\/strong> specifica il prefisso da utilizzare per i percentili nell’output.<\/span><\/p>\n
 Gli esempi seguenti mostrano come utilizzare ciascun metodo con il seguente set di dati in SAS:<\/span> <\/p>\n
 \/*create dataset*\/\ndata<\/span> original_data;\n    input<\/span> team $points;\n    datalines<\/span> ;\nAT 12\nAt 15\nAt 16\nAt 21\nAt 22\nAt 25\nAt 29\nAt 31\nB16\nB22\nB25\nB29\nB 30\nB 31\nB 33\nB 38\n;\nrun<\/span> ;\n\n\/*view dataset*\/\n<\/span>proc print<\/span> data<\/span> = original_data;<\/span><\/span><\/strong> <\/pre>\n
\"\"<\/p>\n
 Esempio 1: calcolare un valore percentile specifico<\/strong><\/span><\/h3>\n
 Il codice seguente mostra come calcolare il 70\u00b0 percentile per la variabile punti<\/strong> :<\/span> <\/p>\n
 \/*calculate 70th percentile value for points*\/\n<\/span>proc univariate<\/span> data<\/span> =original_data;\n    var<\/span> points;\n    output out<\/span> =percentile_data\n    pctlpts<\/span> = 70<\/span>\n    pctlpre<\/span> = P_;\nrun<\/span> ;\n\n\/*view results*\/<\/span>\nproc print<\/span> data<\/span> =percentile_data;\n<\/strong><\/span><\/pre>\n
\"\"<\/p>\n
 Il valore al 70\u00b0 percentile risulta essere 30<\/strong> .<\/span><\/p>\n
 Esempio 2: calcolare pi\u00f9 valori percentili specifici<\/strong><\/span><\/h3>\n
 Il codice seguente mostra come calcolare i valori del 70\u00b0, 80\u00b0 e 90\u00b0 percentile per la variabile punti<\/strong> :<\/span> <\/p>\n
 \/*calculate 70th, 80th, and 90th percentile value for points*\/\n<\/span>proc univariate<\/span> data<\/span> =original_data;\n    var<\/span> points;\n    output out<\/span> =percentile_data\n    pctlpts<\/span> = 70 80 90<\/span>\n    pctlpre<\/span> = P_;\nrun<\/span> ;<\/strong><\/span> <\/pre>\n
\"\"<\/p>\n
 Ecco come interpretare il risultato:<\/span><\/p>\n