/* SleepTheHardWay.sas */
title "Student's Sleep data with a classical mixed model";

data bedtime;
     infile '/folders/myfolders/studentsleep.data.txt' firstobs=2; 
                                             /* Skip the header */
     input patient xsleep1 xsleep2; 
     sleepdif = xsleep2-xsleep1; 

proc print;
     title2 'Data in multivariate format';

proc means n mean stddev t probt;
     title2 'Matched t-test';
     var xsleep1 xsleep2 sleepdif;

/* Make a data table in univariate format */

data unisleep;
     set bedtime;                      /* output writes a case */
     Subject=patient; Drug=1; ExtraSleep=xsleep1; output;
     Subject=patient; Drug=2; ExtraSleep=xsleep2; output;
     keep Subject Drug ExtraSleep;

proc print;
     title2 'Data in univariate format';

proc glm plots=none;
     title2 'Repeated measures ANOVA: Compare t = 4.06, p = 0.0028';
     class Subject Drug;
     model ExtraSleep = Subject Drug;
     random Subject / test;

/* So F = t-squared except for rounding error. */