data a;
infile 'E:\Reading\Teaching\MSCMDS_2005\DataFiles\rattox.dat';
input group treat sex animal day weight;
day_2=day*day;
run;

/*---------------------------------------------------------------------
| RATTOX.SAS : Rat toxicology data.                                   |
|                                                                     |
| The treatments are : 1 = control, 2 = compound A at 4mg,            |
| 3 = A at 20mg, 4 = A at 100mg and 5 is compound B at 100mg.         |
|                                                                     |
| Sex is as follows : 1 = males, 2 = females.                         |
|                                                                     |
| Groups are as follows : 1 to 5 are males on treatments 1 to 5       |
| 6 to 10 are females on treatments 1 to 5.                           |
|--------------------------------------------------------------------*/

proc print;
run;
proc mixed covtest;
class group treat sex animal;
model weight= day group*day/ s  chisq;
random int day / subject= animal(group) type=un g;
run;

proc mixed covtest;
class group treat sex animal;
model weight= day group group*day day_2 group*day_2/ s  chisq;
random int day day_2 / subject= animal(group) type=un g;
run;