The MDS Procedure

The VAR statement specifies the numeric variables in the DATA= data set that contain similarity or dissimilarity measurements on a set of objects or stimuli. Each variable corresponds to one object.

If the VAR statement is omitted, all numeric variables that are not specified in another statement are used.

To analyze a subset of the objects in a data set, you can specify the variable names corresponding to the columns in the subset, but you must also use a DATA step or a WHERE clause to specify the rows in the subset. PROC MDS expects to read one or more square matrices, and you must ensure that the rows in the data set correctly correspond to the columns in number and order.