Free SAS Tutorials : Basics of SAS programming

SAS stands for STATISTICAL ANALYSIS SYSTEM

SAS software (Click here for free SAS software access)

SAS has 3 windows:

1. Editor/code window : A place where we write our codes/programs.
2. Log window : All the executed SAS codes are printed in this window along with any error or warning messages. A PUT statement can be used to print the output in the log window.
3. Output window(non default window) : Appears only where there is an output from the sas program mostly whenever a dataset is created(dataset is a sas file which has data in the form of rows(observations) and columns(variables)).
4. Result window : Place where we can see the result from the sas code which is only viewed but is not saved.

Editor/code window

Log window

Output window

How does a SAS data looks like?

A SAS data set contains data values that are organized as a table of observations (rows) and variables (columns) that can be processed by SAS software.

The below image has 4 variables i.e, name, age, height and weight and 3 observations.

SAS Components

•  Base SAS – Basic procedures and data management 
•  SAS/STAT – Statistical analysis 
•  SAS/GRAPH – Graphics and presentation 
•  SAS/ETS – Econometrics and Time Series Analysis 
•  SAS/INSIGHT – Data mining 
•  Enterprise Miner – data mining 
•  Enterprise Guide - GUI based code editor & project manager 
•  SAS EBI - Suite of Business Intelligence Applications 

Basic SAS programming guidelines:

1. Each statement ends with a semicolon.
• Example: Data sample; Input id;
2. A single statement can be written in multiple lines or multiple sas statements can be written in single line.
3. SAS statements are not case sensitive.
4. Every data step and proc step should end with RUN statement and proc sql should end with QUIT statement
• Example - data step: Data sample;var1=10;run;
• Example - proc step: proc print data=sample;run;
• Example - proc sql;select * from sample;quit;
5. All the sas variable names should be between 1 to 32 characters.
6. SAS variable names can start with a underscore (_) or character but cannot start with number. Blank spaces and few special characters like $,%, & are not allowed in the variable names.
7. SAS code comments are specified in two ways. 
• commenting starts with  asterisk(*) and ends with semicolon(;) --- * comment ;
• Example: 
• * mention the comments;
• * comment line 1

                              * comment line 2;

• commenting starts with /* and ends with  */ --- /* comment */
• Example:

                              /* comment line 1
                                  comment line2

                                  comment line 3 */

SAS Programming:

Every sas code starts with either a DATA step or PROC step

DATA step

• Data step starts with keyword DATA and ends with RUN statement
• One of the way to create a dataset
• Data step is used to get the data from a raw file like excel ,text etc. 
• It is used to manage the data, create new variables, transform the data.
• Create variables and observations

Sample code:

Output:

PROC step

• Proc step starts with keyword PROC and end with RUN statement.
• Proc steps are nothing but inbuilt procedures available in SAS. 
• These are used to analyze the data, view the data and generate reports.

Sample code:

Output:

<- Previous