SAS 9.4 Language Reference, 6th Edition

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 data sets

so that the observations are grouped by common variable values. You can use BY-group

processing in both DATA and PROC steps.

The most common use of DATA step BY-group processing is to combine multiple SAS

data sets and use the BY statement with one of the following language elements:

• SET statement

• MERGE statement

• MODIFY statement

• 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 22, “BY-Group

Processing in the DATA Step,” on page 459.

• 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 23, “Reading, Combining, and Modifying SAS

Data Sets,” on page 475. For even more extensive examples of BY-group processing,

see Combining and Modifying SAS Data Sets: Examples.

175

• For information about the BY statement, see Statements in SAS DATA Step

Statements: Reference.

• For information about how to use BY-group processing with other software products,

see the SAS documentation for those products.

176 Chapter 10 • By-Group Processing in SAS Programs