Wednesday, April 15, 2009

Learn SAS Programming

How to determine the executing program name and path programatically:

Oftentimes, I was asked to keep the name and path of the executing program in the FOOTNOTE of the generated table or listings.I have always created a macro variable using the %let statement and, then I called the Macro variable in the footnote statement to get the name of the program. Eventhough it is simple.. it may not be suitable when we write application which need to self document...

Read more at: http://studysas.blogspot.com/2009/04/how-to-determine-executing-program-name.html
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How to check if a variable exist or not:
In SAS sometimes, we need to check whether the variable is exist in the dataset or not, we usually run the proc contents program and physically check if the variable exist in the dataset or not.If we want to check it programmatically, then use the following code....

Read more at: http://studysas.blogspot.com/2009/04/how-to-check-if-variable-exists-in-sas.html
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How to check if the File is exist or not in SAS:
Guys… Let me try explaining how to check if the file exist in the library or directory using SAS.Here I am writing a macro to check if the file exist in the directory or not.Here is the way to

check it… http://studysas.blogspot.com/2009/04/how-to-check-if-file-is-exist-or-not-in.html
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SAS programming errors we make..... can be deadly sometimes
The errors I will list here will be very few in number. They are errors that you will likely make at some time if you do not remain alert. These errors could have serious consequences so that is why I have described them as "deadly errors".

Read more at: http://studysas.blogspot.com/2009/03/sas-programming-errors-we-made-can-be.html
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Proc Sort NODUP vs NODUPKEY

Somany times people from my orkut community asked me what is the real difference between the Proc sort Dodup and the Proc Sort nodupkey. I always wanted to answer the question in a better way…. and folkes… here is the answer ..... A common interview question for SAS jobs is "What is the difference between proc sort nodup and proc sort nodupkey?". The answer the interviewer is expecting is usually "proc sort nodup gets rid of duplicate records with the same sort key but proc sort nodupkey gets rid of other records with the same sort key". However, this is not correct.
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PROC TRANSPOSE: How to Convert Variables(columns) into Observations(ROWS) and Observations(ROWS) into Variables(Columns)

During my early days as a SAS programmer, I get confused very easily with PROC TRANSPOSE. I mean, I get confused with what are the variables that I need to include in BY statement and ID statement as well as in VAR statement.

Read more at…:http://studysas.blogspot.com/2009/03/proc-transpose-how-to-convert.html

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Displaying the Graphs (Bar charts) using PROC GCHART in SAS
Displaying the Graphs (Bar charts) using PROC GCHART in SAS :Just a day ago, I have received a question on Graphs in my orkut community, which prompted me to create following examples.Below are 5 different types of Graphs were produced (including 3d graphs) using Proc Gchart.

Read more at: http://studysas.blogspot.com/2009/03/displaying-graphs-bar-charts-using-proc.html
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Change all missing values of all variables into zeros/putting zeros in place of missing values for variables

I always wondered how do I convert missing values for all the variables into zeros and In this example the I have used array to do the same. The variable list includes ID and Score1 to score6.Using simple array method we can change all the missing value for the variables score1 to score6 to 0.

Read more at:http://studysas.blogspot.com/2009/03/change-all-missing-values-of-all.html
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How to Save LOG file in the required location:

Here is the simple code which allows us to save the log file in the required location. Use Proc printto procedure to save or print the log file. filename dsn ‘C:\Documents and Settings\zzzzzzzzzzzz\Desktop\LOGfile.lst'

Read more at:http://studysas.blogspot.com/2009/03/how-to-save-log-file-or-what-is-proc.html

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Calculating group totals and the counts within each group
Sample 25217: Calculating group totals and the counts within each group This example uses the SUM() function to sum the AMOUNT column, creating a new column named GRPTOTAL with a COMMA10. format. The COUNT() function counts the number of occurrences of STATE within each group. The GROUP BY clause collapses multiple rows for each group into one row per group, containing STATE, GRPTOTAL and the COUNT.

Read more at: http://studysas.blogspot.com/2009/03/calculating-group-totals-and-counts.html
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How to customize page numbers in RTF output

In SAS 9.1, are there easier ways to customize page numbers in RTF output?
Yes, beginning with SAS 9.1, page numbers can be customized in the RTF destination by using an escape character and the {thispage} function, {lastpage} function, {pageof} function, or all three:

Read more at: http://studysas.blogspot.com/2009/03/how-to-customize-page-numbers-in-rtf.html
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How to calculate number of years and number of days between 2 dates;
How to calculate number of years and number of days between 2 dates;Exploring the yrdif and datdif functions in SAS as well as INTCK function:There are several ways to calculate the number of years between two dates and out of all the methods, YRDIF function results the most accurate value.

Read more at: http://studysas.blogspot.com/2009/03/how-to-calculate-number-of-years-and.html
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How to create a comma separated file (.csv) of a SAS dataset?
IN SAS programming, we often require outputting the dataset in different formats like EXCEL and CSV etc and here are the five different ways to export the SAS dataset into .csv file.

Read more at: http://studysas.blogspot.com/2009/02/how-to-create-comma-separated-file-csv.html
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How to Import Excel files into SAS

Microsoft Excel spreadsheets can be read from SAS in several ways. Two of these will be demonstrated here. First, PROC IMPORT allows direct access to Excel files through SAS/Access to PC File Formats or access to Comma-Separated (CSV) files through Base SAS. The second method uses the Excel LIBNAME engine.

Read more at: http://studysas.blogspot.com/2009/02/how-to-import-excel-files-into-sas.html
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How to store a number more than 8 digits for a numeric variables
Q&A: numeric variables length more than 8? We all know that the default length of the numeric variables in SAS is 8 and if suppose I want to store a number lets say (12345678910, which has a length 11 to numeric variable) to variable total, what should I do?

Read more at: http://studysas.blogspot.com/2009/02/how-to-store-number-more-than-8-digits.html
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Options VALIDVARNAME=UPCASE
VALIDVARNAME= V7 UPCASE ANYVALIDVARNAME= option is generally used in SAS whenever we want to control the SAS variable names in the dataset.

Read more at: http://studysas.blogspot.com/2009/02/options-validvarnameupcase.html
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How to merge data sets with a common variable?

Here is the simple way of merging the data sets with a common variable if the datasets has the same prefix name.For example: col1-col10, dsn1-dsn 7 , or data1 to data10 with common variable of ID.Considering we have 10 datsets and all of them having the same prefix data;

Read more at: http://studysas.blogspot.com/2009/02/merging-data-sets-with-common-variable.html
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Merging the data sets with a common variable if the datasets has the same prefix name?

For example: col1-col10 dsn1-dsn 7 data1 to data6 with common variable of Usubjid.here is the example, I have 7 datasets i need to merge and each of them having the common variable(usubjid) to merge, and all the datasets having the same prefix dsn(dsn1 to dsn7).

Read more at: http://studysas.blogspot.com/2009/02/merging-data-sets-using-macro-code.html
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when to use &,&&,and &&&,how do we distinguish(Multiple Ampersands) and Diff. Between single dot and double dots in macros
Here are the 2 important questions always comes up in our minds,(& vs && vs &&& and single dot and double dots) when we are dealing with macros for the first time and here are the answers for them.I did find a very good regarding the above topics in the one of the SAS forums and IAN WHITLOCK explained it very clear.

Read more at: http://studysas.blogspot.com/2009/02/3when-to-use-do-we-distinguishmultiple.html
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How can I count number of observations per subject in a data set?

We always have this question in mind, while we do the SAS programming and here is the simple answer for that, we just need to use SUM statement and the FIRST.variable in the SET statement and then the RETAIN statement to calculate the observations count per subject.

Read more at: http://studysas.blogspot.com/2009/02/how-can-i-count-number-of-observations.html
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How to remove the duplicate observations in the dataset using PROC SQL, DATASTEP/PROC SQL/or PROC SORT etc?

Before using a particular step to remove the duplicate observations, we should understand that the duplicate observations are pertaining to the key variables like usubjid, treatment, patientno. etc, which are unique or exact duplicates( 2 or more observations has the duplicates with respect to all the variables in the dataset).If the observations are exact duplicates with respect to all the variables in the dataset, we can remove the exact duplicates by:

Read more at: http://studysas.blogspot.com/2009/02/how-to-remove-duplicate-observations.html
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How to scan more than 20 records to determine variable attributes in EFI:

In Versions 7 and 8 of the SAS System, by default the Import Wizard, PROC IMPORT and the External File Interface (EFI) scan 20 records to determine variable attributes when reading delimited text files.Changing the default setting can only be done for EFI in Version 7, Release 8 and Release 8.1. Beginning in Release 8.2 changing the default setting is applicable to the Import Wizard, PROC IMPORT and EFI.

Read more at: http://studysas.blogspot.com/2009/02/how-to-scan-more-than-20-records-to.html
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SAS Sample Programs:
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Base SAS Certification Summary---Functions:
SAS Functions can be used to convert data and to manipulate the values of character variables. Functions are written by specifying the function name, then it's arguments in parentheses. Arguments can include variables, constants, or expressions. Although arguments are typically separated by commas, they can also be specified as variable lists or arrays.
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SAS Certification Assignments
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HOW TO CREATE A SAS TRANSPORT(XPT) FILE
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How to Debug the SAS code:

Question:I have a huge SAS program that isn't working. The results I get are not right but there are no errors or warnings in the SAS log. How can I figure out where I went wrong?
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