I want to generating data with a known correlation structure. I use proc iml and this codes. proc iml;   n = 5;   r = {1 .07 .25 .6, .07 1 .07 .25, .25 .07 1 .07, .6 .25 .07 1};   print r;   c = root(r);   print c;   z=j(n,4,.);     do i = 1 to n;                   do j = 1 to 4;                    z[i,j]=rannor(-99);                   end;                 end;   print z;     d = z*c;   print d;   x1 = d[,1];  x2=d[,2]; x3=d[,3]; x4=d[,4];   print x1 x2 x3 x4;   create mvn var{x1 x2 x3 x4};   append; quit; proc print data = mvn; run; It is okey but I want to iteration. I've tried many codes, but so far I did not succeed. How can I make 20 replicate? And also I want to generate ordinal data. How I can do it? Thanks for your help... ... View more