sas training session 1

7/29/2019 SAS Training Session 1

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SAS Training Session 1

Getting Started with SAS

Sun Li

Centre for Academic Computing

[email protected]
mailto:[email protected]:[email protected]


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Outline

Section 1: Getting to know SAS See an overview of SAS

Explore the SAS workspace

Work with SAS data sets

Create and run SAS programs Work with SAS dates and times

Section 2: Exploring sample codes on SAS DATA steps

Read SAS data sets from raw data format or existing SAS data set

Manage data

Use SQL to query & combine SAS data sets


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Software Installation

Faculty:

CAC website: https://mercury.smu.edu.sg/research_portal/index.asp

=> Software Requisition

Postgraduate students

Have your supervisors consent. Please ask your supervisor to:

Drop us a consent email to [email protected], stating the reason

for request and students detail.

Or, directly raise Software Requisition request from CAC website ,stating the reason and students detail.

CAC Support Engineer will contact you once we receive

your request.
https://mercury.smu.edu.sg/research_portal/index.aspmailto:[email protected]://mercury.smu.edu.sg/research_portal/index.asphttps://mercury.smu.edu.sg/research_portal/index.aspmailto:[email protected]://mercury.smu.edu.sg/research_portal/index.asp


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See an overview of SAS

Data accessYou can read raw data in almost any format, from any kind of file, including variable-length

records, binary files, free-formatted dataeven files with messy or missing data.

Managing your dataAfter you've accessed your data, you can use the SAS programming language to manipulate it

any way you choose. For example, you can format your data, create variables, use functions to create data

values, subset data, perform conditional processing, merge data sources, etc.

Analysis & PresentationSAS provides a powerful data analysis tools. You can create graphs, generate a variety of

statistics and models. For reporting and displaying results, SAS gives you an almost limitless number of

visually appealing output formats: HTML format, PDF, PostScipt, RTF and colorful graphs.


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Solution and Tool menus: A set of ready-to-use solutions,

applications, and tools.

Help menu:


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The most commonly used SAS files:

SAS data set: *. sas7bdat

SAS program file: *. sas

SAS list file/ procedure output: *. lst

SAS log file: *. log

Spreadsheet data format:


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SAS library: All SAS files are stored in SAS library. Its a group of files in the same folder or directory.

To access a library, you assign it a name (also known as a libref, or library reference).

librefmust be 8 characters or less.

The full reference to a SAS file is libref.filename.


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Pre-assigned SAS libraries: Sashelp: a permanent library that contains sample data and other files that control how

SAS works at your site. This is a read-only library.

Sasuser: a permanent library that contains SAS files in the Profile catalog that store yourpersonal settings.

Work: a temporary library for files that do not need to be saved from session to session.

Manage files in a SAS library: Open: double-click to open library and file.

View data property: right-click and select Properties. Copy files: click and drag under Show Tree mode. With the Explorerwindow active, goto

menu View-> Show Tree.

View column format: open SAS data file and right-click column heading, and selectColumn Attributes.


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SAS data formats & informats: Formats are variable attributes that affect the way data values are written. General form

of a format is:

format.

$ indicates a charater format; format is a format name;

wis total width including decimal places and special characters;

Period . requires delimiter;

dis the number of decimal places.

Example:

Data 12234.21 KATHY 12,234.21 $12,234.21

Format 8.2 $5. COMMA9.2 DOLLAR10.2

An informat (input format) is the instruction that specifies how SAS reads raw data. Itsgeneral form is the same as SAS formats.


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Create and run SAS programs

Three major steps:

DATA step Enter, manage and manipulate data

Merge data, recode, label and format data Convert non-SAS data sets into SAS data sets

PROC step Conduct statistical analysis & other procedures

Output data into tables and graphs

Convert data into other formats

Macro Rationalize the repetitive sections of programs

Undergo the preprocessing


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Components of SAS programs: SAS statements:

begin with an identifying keyword

end with a semicolon.

SAS steps begin with a DATA statement or a PROC

statement.

end with a RUN statement or a QUITstatementor the beginning of another step.

SAS ignores spaces, carriage returns, or extra lines.

To write a comment: Begin with an asterisk * and end with; semicolon

Begin with/* and end with */

SAS statements and commands are not case sensitive.

SAS keywords are color-coded.

Question:How many SAS statements ?

How many SAS steps ?


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Submit SAS programs and view

output: Select program lines and click menu Run -> Submit.

Program output will be displayed in the Output windowif there is any output. For graphs, a Graph window will

pop in.

Save SAS programs and

output: With the Editor window / Output window active, click

menu File -> Save / Save as.


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OperatorsOperator Operation Example

** Exponentiation x**2

x**.5

* Multiplication x*y

x*12/ Division year/12

+ Addition dose1+dose2

- Subtraction x-y

Operator Alter. Meaning

= eq Equal

^=

~=

ne Not equal

> gt Greater than

< lt Less than

>= ge Greater than orequal to


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Work with SAS dates and times

SAS datetime value: A value representing the number of seconds between January 1,

1960 and an hour/minute/second within a specified date.

Common Informats for Dates:

July 4, 1776

11:30:23

Jan 1, 1960

midnight

April 22, 1989

16:10:45

-5790400177 0 92488384

Date expression SAS date informat SAS date value

02Jan2000 DATEw. 14611

02Jan00 DATEw. 14611

01/02/2000 MMDDYYw. 14611

January 02, 2000 WORDDATEw. 14611

Sunday, January 02, 2000 WEEKDATEw. 14611


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Work with SAS dates and times

However, you can override the default and change the value of byspecifying the YEARCUTOFF= option in the OPTIONS statement to change .

options yearcutoff=1950;

Date expression Yearcutoff=1920

(by default)

Yearcutoff=1950

12/07/41 12/07/1941 12/07/2041

18Dec15 18Dec2015 18Dec2015

04/15/30 04/15/1930 04/15/2030

15Apr95 15Apr1995 15Apr1995


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Section 1: Getting to know SAS

We have learnt in Section 1:

SAS windows

SAS files

SAS library

SAS data formats & informats

SAS program steps & statements

SAS operators

SAS date & time values


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Create SAS data sets

Create a SAS library: To refer a SAS file in a permanent library, use two-level name: libref.filename.

To refer a SAS file in a Work library (temporary library), we can omit the libref workand write

filename directory.

Example: libname sas1 E:\lsun';


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Read external raw data:Standard and non-standard format data:

Example of standard numeric data: 15 -15 15.4 +1.23 1.23E3

Example of nonstandard numeric data: 5,000 $1,000.00 10/31/02 (23)

Three methods to read data into SAS as a SAS data set:

Formatted input:

standard and nonstandard character and numeric data

calendar style date values and convert them to SAS date values

Column input: data in fixed columns

standard character and numeric data

Point-and-click: SAS Import Wizard

Click menu File -> Import data

Microsoft Excel *.xls, Comma separated values *.csv, Tab limited file *.txt, some database data sets.


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Example:sp1.txt

0,70,4,1,1,general,4feb1989

1,121,4,2,1,vocati,11nov1989

0,86,4,3,1,general,22oct1991

0,141,4,3,1,vocati,4feb1993==============================

** read standard and nonstandard data;

DATA sas1.sp1;infile E:\lsun\sp1.txt' dlm=',' ;input gender id race ses schtyp prgtype $ date: date9.;RUN;

DATA sas1.sp2;infile E:\lsun\sp2.txt' ;input name $ 1-20 age 21-22 gender $ 23;RUN;

infile: identifies an external raw data file to read.

input: lists variable names in the input file.

sp2.txt

Billy Ray Washington 12M

Sally Hamrick 19M

Robert J. Castle 45M

Glenda Smith-Neil 21F

Codebook for sp2.txt:

Variable name Column number

Name 1-20

Age 21-22

Gender 23


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Create SAS data sets from direct input:** create SAS data set from direct input;DATA quarter1;length Department $ 7 Site $ 8;input Department Site Quarter Sales;

datalines;Parts Sydney 1 4043.97Parts Atlanta 1 6225.26Parts Paris 1 3543.97Repairs Sydney 1 5592.82Repairs Atlanta 1 9210.21Repairs Paris 1 8591.98Tools Sydney 1 1775.74Tools Atlanta 1 2424.19Tools Paris 1 5914.25;RUN;PROC PRINT data=quarter1;RUN;

length: indicates length of variables.

datalines: indicates internal data.


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Manage SAS data sets

Sort and Print data:

** sort and print data ;PROC CONTENTS data=sas1.prdsale;RUN;

PROC CONTENTS nods data=work._all_;RUN;

PROC PRINT data=sas1.prdsale(firstobs=100 obs=200);RUN;

PROC PRINT data=sas1.prdsale;where year=1993;var actual predict product year;RUN;

PROC SORT data=sas1.prdsale;by product descending actual;RUN;PROC SORT data=sas1.prdsaleout=sortsale;by product;RUN;

PROC CONTENTS: displays thedescriptor portion of a SAS data set

PROC PRINT: displays the data portionof a SAS data set.

PROC SORT: sorts a SAS data set

where: selects observations that meet acertain condition.

var: gives the variable list;


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Subset data: SET statement:

** writing to a single SAS data set;DATA prdsale;set sashelp.prdsale;RUN;PROC PRINT data=prdsale (obs=10); RUN;DATA lowsale;set prdsale;if predict < 500;RUN;PROC PRINT data=lowsale (obs=10); RUN;

set: reads data set.

Keep /drop: keeps/dropsnamed variables.

if-then-else: executes astatement on if thecondition is true.

DATA diffsale;set prdsale;diff=actual-predict;drop actual predict;RUN;

DATA sale_cat;length cat $ 8;set prdsale;if 0


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DATA product_sample;do i=1 to 1440 by 10;set prdsale point=i;if _error_ then abort;output;end;stop;RUN;PROC PRINT data=product_sample (obs=10); RUN;

do-end: generates an iterative DOloop process.

point-stop: accesses the observationdirectly.

abort: goes out of loop;

output: invokes an explicit output

** Writing to multiple SAS data sets;DATA lperf mperf hperf;drop cat;

set sale_cat;if cat='low' then output lperf;else if cat='moderate' then output mperf;else output hperf;RUN;PROC PRINT data=lperf (obs=10);PROC PRINT data=mperf (obs=10);PROC PRINT data=hperf (obs=10);RUN;


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Data conversion:

**character-to-numeric conversion;DATA conversion1;cvar1='32000';cvar2='32,000';cvar3='03may2008';cvar4='050308';nvar1=input(cvar1, 5.);nvar2=input(cvar2, comma6.);nvar3=input(cvar3, date9.);nvar4=input(cvar4, mmddyy6.);RUN;PROC CONTENTS data=conversion1; RUN;PROC PRINT data=conversion1; RUN;

input: explicitly convert charactervalues to numeric values.

NumVar=INPUT(source, informat);

SAS auto converts a character value to a

numeric value when the character value

is used in a numeric context such as an

arithmetic operation or a function taking

numeric arguments.


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**numeric-to-character conversion;DATA conversion2;nvar1=614;nvar2=55000;nvar3=366;cvar1=put(nvar1, 3.);

cvar2=put(nvar2, dollar7.);cvar3=put(nvar3, date9.);RUN;PROC CONTENTS data=conversion2; RUN;PROC PRINT data=conversion2; RUN;

put: explicitly convert numericvalues to character values.

CharVar=PUT(source, format);

SAS auto converts a numeric value to a

character value when the numeric value

is used in a character context such as an

assignment to a character variable or a

function that accepts character

arguments.Note:

Numeric formats right-align the results.

Character formats left-align the results.


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PROC SQL -- query data:Structured Query Language (SQL) is a standardized, widely used language

that retrieves and updates data in tables and views based on those tables.

DATA payroll;input IdNumber $ 1-4 Sex $ 6 Jobcode $ 8-10 Salary 12-16@18 Birth date7. @26 Hired date7.;datalines;1009 M TA1 28880 02MAR59 26MAR921017 M TA3 40858 28DEC57 16OCT811036 F TA3 39392 19MAY65 23OCT841037 F TA1 28558 10APR64 13SEP921038 F TA1 26533 09NOV69 23NOV911050 M ME2 35167 14JUL63 24AUG861065 M ME2 35090 26JAN44 07JAN871076 M PT1 66558 14OCT55 03OCT911094 M FA1 22268 02APR70 17APR911100 M BCK 25004 01DEC60 07MAY88;RUN;


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PROC SQL;create table oildata asselect p.country, barrelsperday 'Production, barrels 'Reserves'

from sas1.oilprod as p, sas1.oilrsrvs as rwhere p.country = r.countryorder by barrelsperday desc;

QUIT;The SELECTclause selects variables with labels assigned. Because the Country

columns are common to both tables, you qualify them in the SELECTand WHERE

clauses with the table alias p that is assigned in the FROMclause. You could also

qualify the columns by prefixing the column names with the table names. TheWHEREclause selects only rows that have matching values for Country.

The ORDER BYclause orders the output in descending order by the BarrelsPerDay

column. Because the column name appears only in the OilProd table, you don't have

to qualify the column name.


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QUIZ 3

See the file QUIZ-SAS1.pdf.


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Resources and books

You may find the following books helpful: Combining and Modifying SAS Data Sets: Examples

The Little SAS Book: A Primer, Second Edition

SAS SQL Procedure User's Guide

Step-by-Step Programming with Base SAS Software

CAC statistical consultation support:

CAC statistical WIKI page:

http://research2.smu.edu.sg/CAC/StatisticalComputing/Wiki/SAS.aspx

Statistical consultation service: [email protected]
http://research2.smu.edu.sg/CAC/StatisticalComputing/Wiki/SAS.aspxmailto:[email protected]:[email protected]://research2.smu.edu.sg/CAC/StatisticalComputing/Wiki/SAS.aspx


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sas training session 1

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