The core of the SAS System is base SAS software. It consists of

# SAS language: It is a programming language that you use to manage data

# Procedure that are software tools for data analysis and reporting

# A macro facility

# A windowing environment called the SAS Display Manager System.

Overview of Base SAS Software

Before analyze the data and produce the final report we have to arrange the data in the order (format) that the software will recognize the data for further processing. SAS will recognize the data in the form of data set. SAS data set consists of two parts i.e.

# Descriptor information: This describes the contents of the SAS data set to the SAS System.

# Data values: Data that have been collected or calculated which is organized into a rectangular structure containing rows called observations and columns called variables

Syntax of SAS language

SAS language consists of statements. Each SAS statement is terminated by semi-colon (;) When SAS program is executed, log and lst (list or output) files are created by the system.

Log file contains the Error messages, Warnings and Notes. Whenever we run the SAS program, the first step is to open the log file and check for the errors, warnings and notes. This will help us the make the SAS program error free. When the log file is no errors, no warnings, no notes (it displays at the bottom of the log file specifying Warnings 0 Errors 0 Notes 0) then we can confirm that the processing is accurate.

Output file It contains the results of the processing. Base SAS mainly completes with two steps called Data Step and Procedure Step.

Data Step It is used to create data sets. Proc Step is used to execute the pre-defined procedures that are used for processing.

Running the System

We can start SAS session with the SAS command. SAS system can be used in different environments like DOS, Windows, NT, Unix, MVS, VMS etc.

SAS programs can be run in the following methods:

# Display Manager Mode: This method is used in windowing environment. We can edit and execute programming statement, display the SAS log and output windows.

# Interactive Line Mode: In this mode, program statements are entered in sequence in response to prompts from the SAS system.

# Non-interactive mode: SAS program statements are stored in an external file and executes immediately.

# Batch mode: we can run SAS jobs in batch mode under host systems batch or background executive.

Data Step

This is the main part to create a data or to describe