The MDS Procedure
MATRIX Statement
MATRIX | MAT | SUBJECT | SUB variable ;
The MATRIX statement specifies a variable in the DATA= data set that contains descriptive labels for the data matrices or subjects. The labels are used in the output and are copied to the OUT= and OUTRES= data sets. Only the first observation from each data matrix is used to obtain the label for that matrix.
If the MATRIX statement is omitted, the matrices are labeled 1, 2, 3, and so on.