BY Statement
- BY variables ;
You can specify a BY statement with PROC CATMOD to obtain
separate analyses of groups determined 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. The
variables are one or more variables in the input data
set.
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 CATMOD
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 (in base SAS software).
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.
When you specify a BY statement with PROC CATMOD, no further
interactive processing is possible. In other words, once
the BY statement appears, all statements up to the
associated RUN statement are executed for each BY group in
the data set. After the RUN statement, no further
statements are accepted by the procedure.
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
