sas 用iml怎么实现 三个正态分布的零均值随机变量

proc iml;
call randseed(12345);
x = j(10,1,.);*用于存储随机数,10行;
m = j(10,3,.);*用于合并三个随机数;
call randgen(x,'NORMAL',0,1); m[,1] = x;
call randgen(x,'NORMAL',0,2); m[,2] = x;
call randgen(x,'NORMAL',0,3); m[,3] = x;
dist = {'A','B','C'};
print m[colname=dist];
quit;