/*
** Lesson 4.2: Dummy Variable Trap
*/
use gpe2;
output file = gpe\output4.2 reset;
load almon[61,3] = gpe\almon.txt;

cexp = almon[2:61,2];
capp = almon[2:61,3];
qt = almon[2:61,1];

pattern = {1 0 0 0,
           0 1 0 0,
           0 0 1 0,
           0 0 0 1};
D = reshape(pattern,60,4);

call reset;
_const = 0;	@ regression without intercept @
_names = {"cexp","capp","q1","q2","q3","q4"};
call estimate(cexp,capp~D);
end;