BY Statement
- BY variables ;
You can specify a BY statement with PROC STDIZE to obtain separate
standardization for observations in groups defined by the BY variables.
If your DATA= 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 STDIZE 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.
When you specify the option METHOD=IN(ds), the following rules are
applied to BY-group processing:
- If the ds
data set does not contain any of the BY variables,
the entire DATA= data set is standardized by
the location and scale
measures (along with the constants for addition
and multiplication) in the ds data set.
- If the ds data set contains some, but not all, of
the BY variables or if some BY variables do not
have the same type or length in the ds data set
that they have in the DATA= data set, PROC STDIZE displays an
error message and stops.
- If all of the BY variables appear in the ds
data set with the same type and length as in the
DATA= data set, each BY group in the DATA=
data set is standardized using the location and scale
measures (along with the constants for addition
and multiplication) from the
corresponding BY group in the ds data set. The BY
groups in the ds data set must be in the same
order as they appear in the DATA= data set. All BY groups in the
DATA= data set must also appear in the ds data set.
If you do not specify the NOTSORTED option, some BY
groups can appear in the ds data set but not in the
DATA= data set; such BY groups are not used in
standardizing data.
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
