SAS Notes

Compiled by : Wilson Suraweera @ CGHR
Contents
Random Numbers in SAS
Data Sub-setting
Selection  of  two Random Samples
Identification and Separation of duplicate records in SAS dataset
Reshape Long list variable dataset to Wide list dataset
Missing values replacement with Means of the respective Variables
Logistic Regression with SAS
SAS made easy using Proc SQL
SAS PROC SQL procedure to access external ODBC data sources
SAS String Data Handling
SAS Missing value arithmetic's
Text analysis - an Epidemiological Case Study by WS - SAS Institute HUG -01 April2011
Reading XPORT transport file into SAS 
External Resources
SAS Knowledge Base - Glossary of SAS Procedures from SAS.com
SAS resources from - UCLA
Logistic regression
          SAS Online Tutor -  Advance SAS Quiz  from SAS Institute
SAS Dinosaur - Old and New way of SAS programming
Paul Dicman's Web Page for SAS- This little old discusses SAS 8, but useful
Global Statements Dictionary - Alphabetical listing and Description of SAS Key words
SAS Study Blog
SAS Canada - User Groups
         

Some useful SAS String Data Handling Functions
--------------------------------
CAT, CATS, CATT, CATX
The CAT functions concatenate and return the values passed.
CAT concatenates values as if the concatenation operator, ||,
were used. CATT removes trailing blanks from each argument
before concatenating (think CAT plus TRIM). CATS strips leading
and trailing blanks before concatenating. CATX is like CATS, but
places a delimiter between values being concatenated. Numeric
values are formatted to character values using BEST32. for
numbers with many digits and BEST12. for numbers with fewer
digits. These functions reduce the need to use the TRIM, LEFT,
and PUT functions with the concatenation operator.
data _null_;
length a b c $ 8;
a = 'some';
b = ' text';
n = 123.456;
c = 'together';
cop = trim(a) || trim(left(b)) ||
trim(left(vvalue(n))) || c;
cat = cat(a, b, n, c);
catt = catt(a, b, n, c);
cats = cats(a, b, n, c);
catx = catx(',', a, b, n, c);
put +1 cop= / +1 cat= / catt= / cats= /
catx=;
run;
Output:
cop=sometext123.456together
cat=some text 123.456together
catt=some text123.456together
cats=sometext123.456together
catx=some,text,123.456,together

------------------------------------------------
SCAN
The SCAN function. Scan allows you to isolate a word ( or group of letters )
in a text string given a definable set of delimiters
data _null_;
array word(4) word1-word4;
string='Here is my string';
do i=1 to 4;
word(i)=scan( string, i, ' ' );
put word(i);
end;
run;
Output:
word(1) = 'Here'
word(2) = 'is'
word(3) = 'my'
word(4) = 'string'
 
SUBSTR, SUBSTRN, LENGTH, LENGTHN 
The SUBSTRN function is like the SUBSTR function, but the
length parameter can be zero. When the length parameter is
zero, a zero length value is returned. SUBSTRN can be useful
with regexp matches that may be zero length. The LENGTHN
function is like the LENGTH function, but with a value that is all
blanks, zero is returned. In this example, notice the NOTE output
when SUBSTR is passed a zero length. SUBSTRN does not
cause a NOTE like this to be output.
data _null_;
length empty $ 8;
substr = substr("some text", 1, 0);
substrn = substrn("some text", 1, 0);
put substr= / substrn=;
length = length(empty);
lengthn = lengthn(empty);
put length= / lengthn=;
run;
Output:
NOTE: Invalid third argument to function
SUBSTR at line XX column XX.
substr=some text
substrn=
length=1
lengthn=0
-------------------------------------------------
VVALUE, VVALUEX
VVALUE takes a variable and returns the value formatted as a
character string. VVALUEX takes a string that contains a variable
name and returns the value of the variable formatted as a
character value. This is like using the PUT function without
having to specify a format. The format used to format values is
the default format for that type. For numeric values, the default
format is typically BEST12. For character values, the default
format is typically $w., where w is the length of the value. The
default format can be changed with the FORMAT statement.
data _null_;
n = 123.456;
a = vvalue(n);
b = vvaluex('n');
put "a = " a $12. / "b = " b $12.;
run;
Output:
a = 123.456
b = 123.456
-----------------------------------------------------
References:
	1. Jason Secosky, SAS, Cary, NC., The DATA step in SAS 9: What's New?,  Revised May 3, 2004, http://support.sas.com/rnd/base/datastep/dsv9-sugi-v3.pdf
 

Learn More  : ftp://ftp.sas.com/techsup/download/sample/datastep/concat_function.html

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