BY Statement
- BY variables ;
You can specify a BY statement with PROC TREE to obtain separate
analyses on observations in groups defined by the BY variables.
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 using the SORT procedure with a similar
BY statement.
- Specify the BY statement option NOTSORTED or DESCENDING
in the BY statement for the TREE 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 using the DATASETS procedure.
For more information on the BY statement, refer to the discussion
in SAS Language Reference: Concepts.
For more information on the DATASETS procedure, refer to the
discussion in the SAS Procedures Guide.
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
