134-30 a hands-on introduction to sas data step programming：134-30一手在sas数据步编程介绍.pdf

SUGI 30 Hands-on Workshops Paper 134-30 A Hands-On Introduction to SAS® DATA Step Programming Debbie Buck, D. B. P. Associates, Houston, TX ABSTRACT The SAS DATA step is one of the most powerful and versatile software tools available for handling and manipulating data files, especially large data sets. It is also sometimes somewhat confusing to SAS programmers as to what the different statements do, what the correct syntax is for these statements, and how they can help you achieve your goals. In this workshop we will examine how to get data into a SAS data set, how to create new variables or modify existing variables, how to conditionally handle variables or observations, how to handle a group of variables in the same way, and how to control which observations are written to the SAS data set. INTRODUCTION To become familiar with SAS DATA step programming, we will discuss a number of commonly used DATA step statements and then work through exercises utilizing these statements. Some of these will include: • How to create a SAS data set (DATA statements), • How to get data into a SAS data set (INFILE/INPUT, SET, MERGE statements), • How to create or modify variables (Assignment statements), • How to conditionally execute statements (IF-THEN/ELSE statements), • How to select specific observations (Subsetting IF statements), • How to process a group of variables (AR