SAS 9.4 Language Reference, 3rd Edition

Chapter 10

By-Group Processing in SAS

Programs

Definition of BY-Group Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

References for BY-Group Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

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 427.

• For information about how to use BY-group processing with SAS procedures, see

Chapter 2, “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 443. 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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156 Chapter 10 • By-Group Processing in SAS Programs