Introduction to SAS

Math 3200 Jan. 2005Jimin Ding

Why SAS

• SAS is a powerful and the most widely used statistical package.

• SAS is the standard and official package in many application fields.

• Knowledge of SAS is an asset in many job markets:– “SAS programmer”– “official” statistical package authorized by FDA– Used by all Fortune 500 companies

More about SAS• SAS is NOT free.• SAS does NOT support Mac OS.• SAS is NOT much used for statistical methodological research.• SAS is very different from all other programming languages.• SAS is good at data management and handling data in various

formats.• SAS can be much faster than other statistical packages in

analyzing very large data sets.• SAS supports Structured Query Language (SQL). • SAS is good at routine statistical analyses.• SAS was developed in 70s at NCSU, “Statistical Analysis

System”.

Where to find SAS

• SAS is available on computers in the ArtSci computing lab in Seigle Hall, room 012. https://computing.artsci.wustl.edu/labs/computing

• Access Virtual SAS through campus network https://computing.artsci.wustl.edu/access-virtual-sas

• If you have purchased a SAS license, you may download SAS through wustl https://swdownload.wustl.edu/SAS/sas-depot.shtml

• SAS in Cloud: SAS OnDemand for Academics: http://support.sas.com/ondemand/ http://support.sas.com/software/products/ondemand-academics/manuals/sodaug.pdf

About the Class• We will only demonstrate windowed version SAS. (The

other mode: batch mode/command-line) • The part of SAS we learn is a very small part of SAS:

Base, STAT, GRAPH. (IML, SQL,….)• There are two main components of most SAS

programs: data steps and procedure steps.• A strategy: check the details of the sample code, and

learn details of each procedure when you need them.• Goal: write simple SAS codes to utilize basic statistical

procedures, and understand the output.

SAS Interface

• Program editor: write your SAS program codes (commands and comments), should be saved frequently ; xxx.sas.

• Log window: contain errors, warnings, notes of how SAS interpret your codes, check it every time you run a program; xxx.log.

• Output window: results; xxx.lst.

• Explorer and Results Windows: easy to use as data/file management tools, navigation tool.

SAS Programs• End of the sentence: ;• Beginning of the block:

DATA xxx; PROC GLM;

• End of the block: Run; Quit;

• Comments: /* comments */ * Comments ;

• Case insensitive• Very rigid code format

SAS Sample codes

• Entering data using data step and data importation

• Exploring data using descriptive statistics and graphics

• Inferential statistics: testshttp://www.ats.ucla.edu/stat/sas/modules/default.htm