SAS/IML - something worth to remember

# sasdataset -> matrix
use sas_data;
read all into M; /* read all variables into a matrix M;
print M;

# matrix -> sasdataset
proc iml;
M={1 2 3, 4 5 6, 7 8 9};

create sas_data from M;
append from M
close sas_data

quit;

# pi
pi=constant('PI');

# rank of a matrix
rank=round(trace(ginv(a)*a));