SAS means Statistical Analysis System, which is an integrated set of software products.

• Information retrieval and data management

• Writing reports and graphics

• Statistical analysis, econometrics and data mining

• Business planning, forecasting and decision support

• Operation research and Project management

• Quality Improvement

• Data Warehousing

• Application Development

The basic structure of SAS are

• Program Editor

• Explorer Window

• Log Window

To run program successfully, and you have following basic elements:

• There should be a semi-colon at the end of every line

• A data statement that defines your data set

• Input statement

• There should be at least one space between each word or statement

• A run statement

For example: Infile ‘H: \StatHW\yourfilename.dat’;

The Data step creates an SAS dataset which carries the data along with a “data dictionary.” The data
dictionary holds the information about the variables and their properties.

The logical area in the memory is represented by PDV or Program Data Vector. At the time, SAS creates a
database of one observation at a time. An input buffer is created at the time of compilation which holds a
record from an external file. The PDV is created following the input buffer creation

The data types in SAS are Numeric and Character.

In SAS, the “where” statement does not perform automatic conversions in comparisons.

You can debug and test your SAS program by using Obs=0 and systems options to trace the program
execution in log

The difference between the NODUP and NODUPKEY is that, NODUP compares all the variables in our
dataset while NODUPKEY compares just the BY variables

For DataSet : Data set name/ debug Data set: Name/stmtchk

For Macros: Options: mprint mlogic symbolgen

To display the contents of the SAS dataset PROC print is used and also to assure that the data were read
into SAS correctly. While, PROC CONTENTS display information about an SAS dataset.

The syntax of proc summary is same as that of proc means, it computes descriptive statistics on numeric
variables in the SAS dataset.

Proc glm performs simple and multiple regression, analysis of variance (ANOVAL), analysis of
covariance, multivariate analysis of variance and repeated measure analysis of variance.

SAS INFORMATS are used to read, or input data from external files known as Flat Files ASCII files, text
files or sequential files). The informat will tell SAS on how to read data into SAS variables.

SAS informats are placed in three categories,

• Character Informats : $INFORMATw

• Numeric Informats : INFORMAT w.d

• Date/Time Informats: INFORMAT w.

16. What function CATX syntax does?

CATX syntax concatenate character strings remove trailing and leading blanks and inserts separators.

PROC gplot has more options and can create more colorful and fancier graphics.

Options statement.

The –ERROR-variable ha a value of 1 if there is an error in the data for that observation and 0 if it is not.

It implies that automatic conversion took place to make character functions possible.

Because POINT= reads only the specified observations SAS cannot detect an endoffile condition as it
would if the file were being read sequentially.

FIRSTOBS and OBS option

31st December 1961

INPUT, DATA and RUN…

Compile

When SAS editor looks at Run it starts compiling the data or proc step, if you have more than one data
step or proc step or if you have a proc step. Following the data step then you can avoid the usage of the run
statement.

SAS is considered self documenting because during the compilation time it creates and stores all the
information about the data set like the time and date of the data set creation later No. of the variables later
labels all that kind of info inside the dataset and you can look at that info using proc contents procedure.

Sort them once, can use firstobs = and obs = ,

Functions can used inside the data step and on the same data set but with proc’s you can create a new data
sets to output the results. May be more ………..

I would use TRANSPOSE if the variables are less use arrays if the var are more …………….. depends

In unsorted data you can’t use First. or Last.

First thing is look into Log for errors or warning or NOTE in some cases or use the debugger in SAS data
step.

Check the Log and for data validation things like Proc Freq, Proc means or some times proc print to look
how the data looks like ……..

I think sort them with common variables and use merge statement.

BASE, STAT, GRAPH, ETSBriefly

Match Merging, Direct Access, Format Tables, Arrays, PROC SQL

SAS 9.1.3,9.0, 8.2 in Windows and UNIX, SAS 7 and 6.12

Sampling method using OBS option or subsetting, commenting the Lines, Use Data Null

The result of any operation with missing value will result in missing value. Most SAS statistical
procedures exclude observations with any missing variable vales from an analysis.

Using PROC TRANSPOSE

Proc can be used with wider scope and the results can be sent to a different dataset. Functions usually
affect the existing datasets.

Declare array for number of variables in the record and then used Do loop Proc Transpose with
VARstatement

Will either read or writes all numeric and character variables in dataset.

Using double Trailing @@

The retain statement is used to hold the values of variables across iterations of the data step. Normally, all
variables in the data step are set to missing at the start of each iteration of the data step. What is the order
of evaluation of the comparison operators: + – * / ** ()?A) (), **, *, /, +, –

Using Data Null and put statement

Using Obs=0 and systems options to trace the program execution in log.

It will display the execution of whole program and the logic. It will also display the error with line number
so that you can and edit the program.

It has only to values, which are 1 for error and 0 for no error.

By using ODS TRACE ON

Missing values will be assigned as missing in Assignment statement. Sort order treats missing as second
smallest followed by underscore.

Using Subset functions like IF then Else, Where and Select.

Character as Blank or “ and Numeric as.

INTNX.

When you submit a DATA step, SAS processes the DATA step and then creates a new SAS data set.(
creation of input buffer and PDV)

Compilation Phase

Execution Phase

SAS/Access only process through the databases like Oracle, SQLserver, MsAccess etc. SAS/Connect only
use Server connection.

OPTIONS Statement, Label statement, Keep / Drop statements.

The N=PS option creates a buffer in memory which is large enough to store PAGESIZE (PS) lines and
enables a page to be formatted randomly prior to it being printed.

Proc Sort with nodupkey option, because it will eliminate the duplicate values.

• The main advantage of version9 is faster execution of applications and centralized access of data andsupport.
• There are lots of changes has been made in the version 9 when we compared with the version8. The following are the few:SAS version 9 supports Formats longer than 8 bytes & is not possible with version 8.
• Length for Numeric format allowed in version 9 is 32 where as 8 in version 8.
• Length for Character names in version 9 is 31 where as in version 8 is 32.
• Length for numeric informat in version 9 is 31, 8 in version 8.
• Length for character names is 30, 32 in version 8.3 new informats are available in
• version 9 to convert various date, time and date time forms of data into a SAS date or SAS time.

PROC SQL?

SELECT WEIGHT,

CASE

WHEN WEIGHT BETWEEN 0 AND 50 THEN ’LOW’

WHEN WEIGHT BETWEEN 51 AND 70 THEN ’MEDIUM’

WHEN WEIGHT BETWEEN 71 AND 100 THEN ’HIGH’

ELSE ’VERY HIGH’

END AS NEWWEIGHT FROM HEALTH?

QUIT?

Proc SQL noprint?

Create Table inter.Merged1 as

Select distinct * from inter.readin ?

Quit?