Chapter 10
By-Group Processing in SAS
Programs
Definition of BY-Group Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
References for BY-Group Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
Definition of BY-Group Processing
BY-group processing is a method of processing observations from one or more SAS data
sets that are grouped or ordered by values of one or more common variables. You can
use BY-group processing in both DATA and PROC steps.
The most common use of BY-group processing in the DATA step is to combine two or
more SAS data sets by using the BY statement with a SET, MERGE, MODIFY, or
UPDATE statement. When you create reports or summaries with SAS procedures, BY-
group processing enables you to group information in the output according to values of
one or more variables.
References for BY-Group Processing
• For more information about BY-Group processing, see Chapter 20, “BY-Group
Processing in the DATA Step,” on page 449.
• For information about how to use BY-group processing with SAS procedures, see
“Fundamental Concepts for Using Base SAS Procedures” in Base SAS Procedures
Guide and individual procedures in Base SAS Procedures Guide.
• For information about using BY-group processing to combine information from
multiple SAS data sets, see Chapter 21, “Reading, Combining, and Modifying SAS
Data Sets,” on page 465. For even more extensive examples of BY-group
processing, see Combining and Modifying SAS Data Sets: Examples.
• For information about the BY statement, see Statements in SAS Statements:
Reference.
• For information about how to use BY-group processing with other software products,
see the SAS documentation for those products.
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