An Introduction An Introduction to to

SAS SAS ProgrammingProgramming

Last Updated : 29 June, 2004

Center of Excellence

Data Warehousing

AgendaAgenda

Working with SAS EnvironmentSAS Programming BasicsEditing and Debugging SAS Programs Setting up the SAS SessionCreating Basic Reports and Statistics

ObjectivesObjectives

Learn toWork with and manage your SAS windows Create SAS libraries Explore and manage SAS files Enter and submit SAS programs Create and use file shortcuts.

Explore WindowExplore Window

User toCreate new libraries and SAS files Open any SAS file Consolidation of

disparate information sourcesPerform most file management tasks such

as moving, copying, and deleting files Faster time-to-market for products and services

Create shortcuts to non-SAS files.

Features of Program EditorFeatures of Program Editor

Drag and drop SAS Programs on this window

Specify the number of lines to submit at a time

Recall submitted statements Save contents automatically Clear contents Turn line numbers on and offUse the command line or menus save your program.

Other Windows’ FeaturesOther Windows’ Features

Logview messages about your SAS session and

any SAS programs you submit

Outputbrowse output from SAS programs

Resultnavigate and manage output from SAS

programs view, save, and print individual items of output

Working in SAS Working in SAS

Objectives The structure and components of SAS

programsThe steps involved in processing SAS programs The structure and components of SAS data

setsThe two types of SAS data setsSAS libraries and the types of SAS files that

they contain Temporary and permanent SAS libraries.

Layout of SAS ProgramsLayout of SAS Programs

SAS Programs used to access, analyze, manage and present data

SAS Statements Case insensitiveFree FormatEnds with a semicolon

Styles for Comment - *statement; or /* …*/

Parts of SAS ProgramsParts of SAS Programs

Data Step TO CREATE DATA SETS

put your data into a SAS data set compute the values for new variables check for and correct errors in your data produce new SAS data sets by subsetting, merging, and

updating existing data sets.

Proc Step PROCESS DATA SETS

print a report produce descriptive statistics create a tabular report produce plots and charts.

SAS NAMES (VARIABLES & FILE NAMES)SAS NAMES (VARIABLES & FILE NAMES)NAMES

1 TO 32 CHARACTERS IN LENGTHSTART WITH LETTER (A THRU Z) AND _CAN BE A COMBINATION OF NUMBERS/LETTERS

VARIABLESCHARACTERNUMERIC

FILENAMES2 LEVELLIB - WORK/PERMANENT

Editing SAS ProgramsEditing SAS Programs

the Program Editor window the Enhanced Editor the SAS Notepad window the host editor of your choice

Processing SAS ProgramsProcessing SAS Programs

When you submit a SAS program, SAS software reads the statements and checks them for errors.

When it encounters a DATA, PROC, or RUN statement, SAS software stops reading statements and executes the current step in the program. In our sample program, each step ends with a RUN statement.

Example:-Data Libname.New datasetname;Set Libname.Old datasetname;run;

Overview of SAS Data SetsOverview of SAS Data Sets

Conceptually, a SAS data set is a file consisting of two parts: a descriptor portion and a data portion. Some SAS data sets also contain an index, which enables SAS software to locate records in the data set.

Descriptor Portion name of the data set date and time the data set was created number of observations number of variables. each variable's name, type, length, format,

informat, and label.

Data PortionData Portion

Data PortionTabular Arrangement of dataContains Observations and VariablesVariables can be either Character or numericCharacter variables can be up to 32K longNumeric Values stored as floating point

variables have a default length of 8 bytesSAS can handle up to 32,767 variables

Naming RulesNaming Rules

SAS data set names mustbe 1 to 32 characters in length begin with a letter (A-Z, including mixed case

characters) or an underscore (_) continue with any combination of numbers,

letters, or underscores.

Example:-Payroll Budget1995_1997 _Students

READING RAW DATAREADING RAW DATA

DATA STARTOUTPUT DATA SET

INFILEPOINTER TO EXT FILE

INPUTHOW TO READ INPUT @1 DATE $9. @10 BOARDED 3.;

FLAT FILE VARIATIONS (DELIMITERS, LINE POINTER, LINE HOLD SPECIFIERS)

Variable FormatsVariable Formats

SAS Format & Informat

Data Value

SAS Data Value

Formatted Value

SAS FilesSAS Files

TableViewCatalogMDDB

SAS files are stored in a library.

Creating SAS Data SetsCreating SAS Data Sets

ScheduleCreating Data Sets From Raw FilesSubsetting DataSAS FunctionsReading Fixed Fields, Free Format filesReading from files with multiple rows in a

single line Reading from files with a single row in multiple

linesUnderstanding Data Step ProcessingReading Hierarchical FilesReading Variable Length Records

Base SASBase SAS

data access management analysis presentation

ExampleExample

With SAS, we can join Oracle data on a mainframe computer with an existing SAS data set, create new variables (columns), and produce an interactive graph on your PC.

Types of Files We Can Access Types of Files We Can Access

SAS/ACCESS provides access to these types of files:

Relational databases

DB2 under OS/390

Informix SYBASE

Oracle Rdb DB2 under VM ODBC

ORACLE MS SQL Server DB2 under UNIX or PC

CA-OpenIngres Teradata OLE DB

Contd…Contd…

Non-relational databases and other data sources ADABAS PC File Formats CA-IDMS

IMS-DL/I SYSTEM 2000 software

CA-DATACOM/DB

Contd…Contd…

Enterprise Resource Planning (ERP) systems Baan

PeopleSoft

R/3 SAP BW

Managing Data Managing Data

After we have accessed relevant data, we can use the SAS programming language to manipulate it any way we choose.

For example, we can For example, we can

format the data

create variables (columns)

use operators to evaluate data values

use functions to create and recode data values

subset data

perform conditional processing

merge a wide range of data sources

create, retrieve, and update database information.

Analyzing Data and Presenting Information Analyzing Data and Presenting Information Once our data is in shape, we can use SAS

to analyze data and produce reports. Our SAS output can range from a simple listing of a data set to customized reports of complex relationships.

.

AnalysisAnalysis

Base SAS provides powerful data analysis tools. For example, we can

produce tables, frequency counts, and cross-tabulation tables

create a variety of charts and plots

compute a variety of descriptive statistics, including the mean, sum, variance, standard deviation and more

compute correlations and other measures of association, as well as multi-way cross-tabulations and inferential statistics.

Presentation Presentation

For reporting and displaying analytical results, SAS gives us an almost limitless number of visually appealing output formats, such as

an array of markup languages including HTML4 and XML

output that is formatted for a high-resolution printer, such PostScript, PDF, and PCL files

color graphs that you can make interactive using ActiveX controls or Java applets.

RTF

Explore the SAS workspace Explore the SAS workspace

SAS is designed to be easy to use. It provides windows for accomplishing all the basic SAS tasks we need to do. When you first start SAS, the five main SAS windows open: the Explorer, Results, Program Editor or Editor, Log, and Output windows.

View the Explorer window View the Explorer window

In the Explorer window, we can view and manage our SAS files and create shortcuts to files that are not formatted by SAS. Use this window to

create new SAS libraries and SAS files open any SAS file perform most file management tasks such as moving, copying, and deleting files create file shortcuts.

View the Editor window View the Editor window

We can use either of these windows to enter, edit, and submit SAS programs:

the Program Editor window, which is available on all SAS platforms the Editor window, which is available only in the Windows operating environment.

View the Log window View the Log window

The Log window displays messages about our SAS session and any SAS programs that we submit.

View the Output windowView the Output window

The Output window displays the output from SAS programs that we submit. It automatically opens or moves to the front of our display when we create output.

Contd…..Contd…..

If we create HTML output, we can view it in the Results Viewer window, which is the internal browser for SAS.

View the Results windowView the Results window

The Results window helps us to navigate and manage output from SAS programs that we submit. We can view, save, and print individual

items ofoutput. The Results window is empty until we submit a SAS program that creates output. Then it opens or moves to the front of our display.

View the Solutions and Tools menus View the Solutions and Tools menus Along with windows for working with our SAS files and SAS programs, SAS provides a set of ready-to-use solutions, applications, and tools. We can access many of these tools by using the Solutions and Tools menus.

Create a libraryCreate a library

You can create SAS libraries using a point-and-click interface. Click View Explorer. Click File New. In the New Library window, specify information for the new library. If you

want the library to be created at the beginning of each SAS session, click Enable at startup.

Click OK.

Contd…Contd…

Assigning a libref to reference SAS files Assigning a libref to reference SAS files /*************************************/ /* define SAS library */ /*************************************/ libname sales 'c:\Test'; /*************************************//* create new data set from raw data *//*************************************/ data sales.quarter1; length Department $ 7 Site $ 8; input Department Site Quarter Sales; datalines; Parts Sydney 1 4043.97 Parts Atlanta 1 6225.26 Parts Paris 1 3543.97 Repairs Sydney 1 5592.82 Repairs Atlanta 1 9210.21 Repairs Paris 1 8591.98 Tools Sydney 1 1775.74 Tools Atlanta 1 2424.19 Tools Paris 1 5914.25 ; run; /*************************************/ /* print new data set *//*************************************/ proc print data=sales.quarter1; run;

EditorEditor

Log Log

OutputOutput

LibraryLibrary

Sales

Library & Data SetsLibrary & Data Sets

Assigning a libref to reference DBMS data Assigning a libref to reference DBMS data /*************************************/ /* define SAS library for Oracle */ /*************************************/ libname myorlib oracle user=scott password=tiger path="blunzer:v7" schema=hrdept;/*************************************/ /* define SAS library for DB2 */ /*************************************/ libname mydblib db2 noprompt="user=testuser; password=testpass;database=testdb"; /*************************************/ /* print Oracle table */ /*************************************/ proc print data=myorlib.all_employees; where state='CA'; run; /*************************************/ /* print DB2 table */ /*************************************/ proc print data=mydblib.customers; where state='CA'; run; /*************************************/ /* clear librefs */ /*************************************/ libname myorlib clear; libname mydblib clear;

Read PC database filesRead PC database files

If you have PC database files such as Microsoft Excel spreadsheets, Lotus spreadsheets, or Microsoft Access files, you can use SAS to import these files and create SAS data sets. Once you have the data in SAS data sets, you can process them as needed in SAS. To read PC database files, you use the IMPORT procedure. PROC IMPORT reads the input file and writes the data to a

SAS data set, with the SAS variables defined based on the input records.

ExampleExample

/*************************************//* import the Excel file */ /*************************************/ proc import datafile="c:\test\Accounts.xls" out=sasuser.accounts sheet="Prices"; getnames=no; run; /*************************************/ /* print part of the new data set */ /*************************************/ proc print data=sasuser.accounts(obs=10); run; /*************************************/ /* import the Access file */ /*************************************/ proc import table="customers" out=sasuser.cust dbms=access; uid="userid"; pwd="mypassword"; database="c:\test\east.mdb"; wgdb="c:\winnt\system32\security.mdb"; run; /*************************************/ /* print part of the new data set */ /*************************************/ proc print data=sasuser.cust(obs=5); run;

Read SAS data sets Read SAS data sets

DATA steps that read existing data sets using a SET statement. combine two or more input data sets to create one output

data set merge data from two or more input data sets that share a

common variable update a master file based on transaction records.

Work with SAS data setsWork with SAS data sets

Before we can work with our data in SAS, it must be in a special form called a SASdata set. Conceptually, a SAS data set (also called a table) is a file containing descriptor information and related data values. The file is organized as a table of observations (rows) and variables (columns) that SAS can process. Some SAS data sets also contain an index, which enables SAS to locate records in thedata set.

Contd…Contd…

To work with SAS data sets, you also need to understand how they are stored. All SAS files are stored in a SAS library, which is a collection of files such as SAS data sets and catalogs.In the Windows and Unix environments, a SAS library is typically a group of SAS files in thesame folder or directory.

In some operating environments, a SAS library is a physical collection of files. In others, thefiles are only logically related.

Questions