In my last blog we saw string extraction using perl function. Today we are going to extract and concatenate character string using SAS Scan and Substr functions.
Syntax:
SCAN(argument,n,<delimiters>)
where
argument specifies the character variable or expression to scan. n specifies which word to read. delimiters are special characters that must be enclosed in single quotation marks (' '). If you do not specify delimiters, default delimiters are used. SUBSTR(argument,position,<n>) where argument specifies the character variable or expression to scan. position is the character position to start from. n specifies the number of characters to extract. If n is omitted, all remaining characters are included in the substring. Let us see an example:
In the dataset work.Company there are four columns Name, Age, Sex and SSN.
We wants to create a new data set employeeID with a column named ID which contains unique Identification number for the employees based on their last name and last four digits of their SSN. Company
g
data employeeID; set company; ID = (scan(name, 1, ","))!!(substr(SSN,8,4)); run; proc print data=employeeID; run; Explanation: scan(name, 1, ",") name is the character variable to scan 1 is the position of the word to read "," is the delimiter substr(SSN,8,4) SSN is the character variable to scan. 8 is the character position to start from. 4 specifies the number of characters to extract Result
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Thursday, October 29, 2015
String extraction using SAS Scan and Substr functions
String Extraction Using Perl Regular Expressions (PRX) in SAS
The PRXMATCH function searches source with the perl-regular-expression and returns the position at which the string begins. If there is no match, PRXMATCH returns a zero.
syntax : PRXMATCH (perl-regular-expression, source)
Suppose we have a list of companies and their addresses :
7‑Eleven, Inc.community relations department dallas, TX 75221-0711
20 Century Fox 10201 pico blvd, los angeles, CA 90064
APACHE prime four business park kingswells scotland, United Kingdom
We wish to extract the names of the companies. The names of the companies starts with either a upper-case letters or numbers while their addresses are in the lower-case. To do so we are going to the string extraction with the help of PRXMATCH Function.
Explanaton:
prxmatch ('/\b[a-z]\w*\b/')
In this example we are using forward slashes (/) as perl dilimiters.
\b is word boundary (a space or end-of-line)
[a-z] matches lower-case letters
\w matches any word character (upper- and lowercase letters, blank and underscore)
* matches the previous subexpression zero or more times
As can be seen in the result PRXMATCH function helped us to extract the names of the companies.
Examining the spread of Ebola in different countries using SAS
Examining the spread of Ebola in different countries using SAS
Data source : Sub-national time series data on Ebola cases and deaths in Guinea, Liberia, Sierra Leone, Nigeria, Senegal and Mali since March 2014
Google data sets provides you with current information on the extent of spread of Ebola. We will work on this data set and learn how to
- import excel file into SAS
- write a basic SAS sql program
- Program to import excel file in SAS
proc import DBMS=xls out=work.ebola
datafile="/folders/myfolders/ebola/Ebola1.xls";
run;
After we are done importing the file into SAS, we want to find which country has maximum outbreak of Ebola area-wise .
- The following sql lists the extent of spread of Ebola in different countries. The result gives us country name and the count of different localites affected by ebola.
the output is as follows
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