Step-by-Step Programming with Base SAS 9.4, Second Edition, 2nd Edition

Chapter 11

Creating Subsets of Observations

Introduction to Creating Subsets of Observations . . . . . . . . . . . . . . . . . . . . . . . . . 169

Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169

Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169

Input SAS Data Set for Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

Selecting Observations for a New SAS Data Set . . . . . . . . . . . . . . . . . . . . . . . . . . . 171

Deleting Observations Based on a Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171

Accepting Observations Based on a Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . 173

Comparing the DELETE and Subsetting IF Statements . . . . . . . . . . . . . . . . . . . . . 173

Conditionally Writing Observations to One or More SAS Data Sets . . . . . . . . . . 175

Understanding the OUTPUT Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

Example for Conditionally Writing Observations to Multiple Data Sets . . . . . . . . 175

Avoiding a Common Mistake When Writing to Multiple Data Sets . . . . . . . . . . . 176

Understanding Why the Placement of the OUTPUT Statement Is Important . . . . 177

Writing an Observation Multiple Times to One or More Data Sets . . . . . . . . . . . . 179

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180

Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180

Learning More . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181

Introduction to Creating Subsets of Observations

Purpose

In this section, you will learn to select specific observations from existing SAS data sets

to create new data sets. Specifically, you will learn about the following concepts:

• how to create a new SAS data set that includes only some of the observations from

the input data source

• how to create several new SAS data sets by writing observations from an input data

source, using a single DATA step

Prerequisites

Before proceeding with this section, you should understand the concepts presented in the

following sections:

169