proc iml;
use a;
read all into x;
start parent (x,se);
aa=nrow(x); m=x[+,1];n=aa-m;ma=J(m,2,.);pe=J(n,2,.);t=0;
      do j=1 to aa;
      t=t+1;
     if x[j,1]*j^=j then t=t;
     pe[t,]=x[j,];
      end;
ma=x[n+1:aa,];
a=1+round((n-1)*ranuni(j(50,1,0)));
b=1+round((m-1)*ranuni(j(50,1,0)));
if se=0 then Pa=ma[a,2];
if se=1 then Pa=pe[b,2];
return (pa);
finish;
p1=pa(x,0);p2=pa(x,1);
print P1 P2;
quit;run;


求助程序出错，原因在于t的行数和pe的行数不一致，请帮忙！