filename class 'class3.dat';
options center linesize=78 nodate;
data;
infile class;
input @4 y grp;
if grp=1 then d1=1; else d1=0;
if grp=2 then d2=1; else d2=0;
if grp=3 then d3=1; else d3=0;
c1=d1-d2;
c2=d1-d3;
c3=d2-d3;
c4=d1+d2-2*d3;
c5=d1+d3-2*d2;
c6=d2+d3-2*d1;
proc print;
proc reg;
  model y=d1 d2;
  model y=d1 d3;
  model y=c1 c2;
  model y=c1 c4;
proc anova;
  class grp;
  model y=grp;
run;
quit;