You can specify a BY statement with PROC TCALIS to obtain separate analyses on observations in groups defined by the BY variables in the input data set. When a BY statement appears, the procedure expects the input data set to be sorted in order of the BY variables.

If your input data set is not sorted in ascending order, use one of the following alternatives:

• Sort the data by using the SORT procedure with a similar BY statement.

• Specify the BY statement option NOTSORTED or DESCENDING in the BY statement for the TCALIS procedure. The NOTSORTED option does not mean that the data are unsorted but rather that the data are arranged in groups (according to values of the BY variables) and that these groups are not necessarily in alphabetical or increasing numeric order.

• Create an index on the BY variables by using the DATASETS procedure.

The BY statement is not supported if you define more than one group by using the GROUP statements.

For more information about the BY statement, refer to the discussion in SAS Language Reference: Concepts. For more information about the DATASETS procedure, refer to the discussion in the SAS Procedures Guide.