Westat
,Ian Whitlock
Westat Abstract:
This paper will attempt to explain the secrets to setting SAS variables to missing. Categorizing SAS variables into four types provides a systematic way to unlock such secrets. The 4 types of variables are: Unnamed variables, automatic variables, variables
from SAS data sets and all other variables. The rules governing these four types of variables will be discussed. Two major points will also be emphasized. 1) SAS distinguishes between setting a value to missing at the top of the data step loop from settin
g a value to missing when data is not read. 2) SAS reads in a record only once. Classifying rules into 4 variable types provides a better platform to document when SAS sets variables to missing.
Biography: Robin Jones is a senior systems analyst at Westat working on survey research problems. She has been programming in SAS for 10 years.
Ian Whitlock is a senior systems analyst at Westat working on survey research problems. He has been programming largely in SAS since 1981 using an interactive environment to develop programs for execution in a batch environment. He is active on SAS-L, and
has presented many different papers at national, regional, and local SAS User Group meetings.