SAS Macros Made Easy

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This tutorial explains SAS macros with practical examples. SAS Macro programming is considered as an advanced SAS. Knowing SAS Macros is an advantage in the job market over other candidates. Upon completion of this tutorial, you would understand how to create macros and where they can be used. It's generally said smart programming reduce workload and helps to win over your boss.
SAS Macro for Beginners
What are Macros

Macros are used to automate the repetitive task. It can make your work faster by automating the task that requires writing same lines of code every day. It can also be used when you design a complex algorithm and want to make usage of code user friendly so that people who are not comfortable with programming can use your algorithm.

Introduction to SAS Macro Programming

I. Macro Variables

A macro variable is used to store a value. The value is always character. The character value can include variable-name, letters, numbers or any text you want substituted in your program.

Macro Variables are of two types -
  1. Local -  If the macro variable is defined inside a macro code, then scope is local. It would be available for use in that macro only and gets removed when the macro is finished.
  2. Global - If the macro variable is defined outside a macro code, then scope is global. It can be use any where in the SAS program and gets removed at the end of the session.

5 ways to create macro variables -

The following is a list of various ways to create a macro variable with examples.

1.  %LET

It can defined inside or outside a macro.

The syntax of the %LET statement -
%LET macro-variable-name = value;
%LET x = 5;

Example - To store system date 
%let dt =   &sysdate;

How to use Macro Variables

Macro variables are referenced by using ampersand (&) followed by macro variable name.
& <Macro variable Name> 
To view in log window what macro variable would return, use %PUT statement :
%put &dt.;
%put NOTE : system data is &dt.;
Result :  NOTE : system data is 23DEC16

Notice that unlike the PUT statement the text string is not enclosed in quotes. The quotes are not needed because, unlike in the DATA step, the macro facility does not need to distinguish between variable names and text strings.

2. Macro Parameters

Example : Suppose you are asked to write a macro that returns mean value of a variable. The analysis variable, input and output data sets are dynamic.
%macro test (input =, ivar=, output=);
proc means data = &input noprint;
var &ivar;
output out = &output mean= ;
run;
%mend;
In the above code, test is a macro, input, ivar and output are local macro variables.

How to call a macro -
%test(input=sashelp.heart, ivar= height, output=test);
In this case, we are giving flexibility to users to provide information of input dataset name, the analysis variable and output dataset and the macro returns the mean value of the analysis variable in the output dataset.

3. INTO clause in PROC SQL

Example : Calculate average height and store in a macro variable
proc means data = sashelp.heart noprint;
var height;
output out = test mean= avg_height;
run;
proc sql noprint;
select avg_height into :var1
from test;
quit;
%put &var1; 

 Result :  64.81318

4. CALL SYMPUT routine 

The syntax of CALL SYMPUT :
CALL SYMPUT(macro_varname,value);
data _null_;
set test;
call symput ('var2',avg_height);
run;
%put &var2;
5. ITERATIVE %DO

The syntax of iterative %DO -
%DO macro-variable = start %TO stop <%BY increment>;
. . . text . . .
%END;
Example - 
%macro calcl(start,stop);
%do year = &start %to &stop;
data test;
set yr&year;
year = 2000 + &year;
run;
%end;
%mend calcl;
 How to use conditional processing %IF %THEN ?

In SAS Macros, we can apply conditional statements using %IF %THEN like below -
options mindelimiter=,;
options minoperator;
%MACRO test();
%DO i = 1 %to 9 ;
%if &i in (1,3,5,7,9) %then %do;%PUT i = &i - odd;
%END;
%ELSE %DO;
%PUT i = &i - even;
%end;
%end;
%MEND;
%test();
If you are confused between IF-THEN and %IF-THEN and don't know when to use, check out the link below -
Tutorial : Difference between IF THEN and %IF %THEN

SAS Macro Functions

There are some SAS macro functions which help you to execute various operations within a macro. They are listed below -

1. %EVAL Function

It is used to perform mathematical and logical operation with macro variables.

Example -
%let x = 10;
%let y = 20;
%let z = &x * &y;
%put &z;
It returns "10*20".
%let z2 = %eval(&x*&y);
%put &z2;
It returns 200.

Note :

%let last = %eval (4.5+3.2); returns error as it cannot perform arithmetic calculations with operands that have the floating point values. It is when the %SYSEVALF function comes into picture.
%let last2 = %sysevalf(4.5+3.2);
%put &last2;
It returns 7.7


2. %SYSFUNC Function

There are several useful Base SAS function that are not directly available in Macro, %Sysfunc enables those function to make them work in a macro.
%let dt3 = %sysfunc(date(),yymmdd10.);
It returns  2016-12-23.


3. %STR Function

Usage I : This function removes the normal meaning of following token + – * /, > < = ; “ LT EQ GT LE GE LE NE AND OR NOT blank.

Suppose we need to store PROC PRINT; RUN; command in a macro variable.
%let exmp0 = proc print; run;;
%put &exmp0;
Result : proc print
Since the semicolon following PRINT terminates the %LET statement. It does not consider RUN statement. To workaround this issue, let's use %STR function.
%let exmpl = %str(proc print; run;) ;
%put &exmpl;
Result : proc print; run;

Usage II : Precede with % sign when you use single or double quotation in macro

%let var=%str(a%");
%put &var; 

Result : a"

If you would not use %STR function in the above example, you would not be able to store quotes in a macro variable.

Usage III : It also preserves leading and trailing blanks of the string.
%let dt= %str( a );
%put &dt;
Run the above code and compare it with the code below, you would understand the difference -
%let dt=  a ;
%put &dt;

4. %NRSTR Function

%NRSTR works similar to %STR works except it does not resolve the % and & but stop the macro triggers.
%let exmpl = %nrstr(proc print; run;) ;
%put &exmpl;
 Result : proc print; run;
%put "Difference between %NRSTR(&SYSDATE9) and &SYSDATE9";
Result : "Difference between &SYSDATE9 and 23DEC2016"

In the above case, %NRSTR() stops the &SYSDATE9 macro function.


5. %SCAN Function

It returns the nth word in a string.
%let var = var1 var2 var3;
%let varName =%scan(&var,1,%str( ));
%put &varName;
Result : var1

Concatenation of Macro Variables

Suppose you have 3 macro variables and the third variable is actually a concatenation of the first 2 variables' value.
%let x = var;
%let y = 1 ;
%let var1 = 25;
%let z = &&&x&y;
%put &x &y &z;
Result : var 1 25
&z returns 25 because first && resolves to &, &x resolves to var, &y. resolves to 1. So var1 returns 25
Detailed Tutorial : Multiple Ampersand Macro Variables

How to store list of values in a macro variable

Suppose you have a list of names and you want to store them in a macro variable. It can be done by using SEPARATED BY ' ' keyword in PROC SQL.
data temp;
input name $16.;
cards;
Deepanshu Bhalla
Dave Jhonson
Ram Prasad
;
run;
proc sql;
select name into: myvar separated by ','
from temp;
quit;

%put &myvar; returns  Deepanshu Bhalla,Dave Jhonson,Ram Prasad

In this case, we have used comma(,) as a delimiter. We can use any other delimiter.

How to debug SAS Macros

There are some system options that can be used to debug SAS Macros:

1. MPRINT

MPRINT translates the macro language to regular SAS language. It displays all the SAS statements of the resolved macro code.
options mprint;
%macro test (input =,output=);
proc means data = &input noprint;
var height;
output out = &output mean= ;
run;
%mend;
%test(input=sashelp.heart,output=test);
It returns the following message in LOG window :

MPRINT(TEST):   proc means data = sashelp.heart noprint;
MPRINT(TEST):   var height;
MPRINT(TEST):   output out = test mean= ;
MPRINT(TEST):   run;

2.  MLOGIC

It is very helpful when we deal with nested macros (Macro inside another macro). Often we use %DO loops and or %IF-%THEN-%ELSE statements inside the macro code and LOGIC option will display how the macro variable resolved each time in the LOG file as TRUE or FALSE.
options mlogic;
options mindelimiter=,;
options minoperator;
%MACRO test();
%DO i = 1 %to 9 ;
%if &i in (1,3,5,7,9) %then %do;
%PUT i = &i - odd;
%END;
%ELSE %DO;
%PUT i = &i - even;
%end;
%end;
%MEND;
%test();
In the log window, see what MLOGIC option produces -

MLOGIC(TEST):  %DO loop beginning; index variable I; start value is 1; stop value is 9; by value is 1.
MLOGIC(TEST):  %IF condition &i in (1,3,5,7,9) is TRUE
MLOGIC(TEST):  %PUT i = &i - odd
i = 1 - odd
MLOGIC(TEST):  %DO loop index variable I is now 2; loop will iterate again.
MLOGIC(TEST):  %IF condition &i in (1,3,5,7,9) is FALSE
MLOGIC(TEST):  %PUT i = &i - even
i = 2 - even


3. SYMBOLGEN

It writes the results of resolving macro variable references to the SAS log for debugging.
options symbolgen;
%macro test (input =,output=);
proc means data = &input noprint;
var height;
output out = &output mean= ;
run;
%mend;
%test(input=sashelp.heart,output=test);
SYMBOLGEN:  Macro variable INPUT resolves to sashelp.heart
SYMBOLGEN:  Macro variable OUTPUT resolves to test

Difference between MPRINT and SYMBOLGEN

See the log generated by these two options. MPRINT option prints all the statements within the macro (not just macro variables). Whereas, SYMBOLGEN option prints only the results of macro variables.

How to turn off macro debugging options
options nomprint nomlogic nosymbolgen;
All of these options can be turned off together as specified above. Or one of them can be turned off and remaining ones keep turned on.

Important Tips

1. Use double quotes to reference macro variables.
SAS Macros Tutorial

2. The quotes are not needed in %PUT.
%put NOTE : system data is &dt.;

3. Use Proc PRINTTO for saving log in an external text file.
proc printto log="C:\Users\Deepanshu\Downloads\LOG2.txt" new;
run;
4. Clear LOG and OUTPUT Window
DM "Log" clear continue;
DM "Output" clear continue;

How to call SAS Macro from External Location

1. % INCLUDE
%include "C:\Users\Deepanshu\Downloads\test.sas";
%test;
Suppose your macro is stored in a location and you need to call it from the location. You can accomplish this task using %Include.

2. Autocall Macro Facility and Stored Compiled Macro

Practice Question - Try it Yourself
Calculate distinct number of categories (levels) in variable make in dataset sashelp.cars and store it in a macro variable and later multiply the macro variable by 2.5
Answer it in comment box below 

SAS Tutorials : 100 Free SAS Tutorials

About Author:

Deepanshu founded ListenData with a simple objective - Make analytics easy to understand and follow. He has close to 7 years of experience in data science and predictive modeling. During his tenure, he has worked with global clients in various domains like retail and commercial banking, Telecom, HR and Automotive.


While I love having friends who agree, I only learn from those who don't.

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24 Responses to "SAS Macros Made Easy"

  1. Nice Explanation.Thanks!

    ReplyDelete
  2. Nice one..can you please give us some practical examples on macros...
    Thanks in advance

    ReplyDelete
  3. Nice one..can you please give us some practical examples on macros...
    Thanks in advance

    ReplyDelete
  4. Hi guys,

    I have a dataset :

    data imptbase.data_manipulation;
    infile datalines;
    input filename $ macroname $ sequence;
    datalines;
    area inserted 1
    area deleted 2
    area dropped 3
    country inserted 1
    country deleted 2
    country sorted 3
    ;
    run;

    My intension is to create a macro variable called MAC1 to MAC&mx1 that will hold the macro names. Eg.for filename AREA mac1 will hold value as "Inserted", mac2 will hold "deleted" and so on.

    NOTE : &mx1 will be clear from below given code.
    %macro abc;
    proc sql;
    select count(distinct filename)into :ank from imptbase.data_manipulation;
    %let ank1 = %eval(&ank);
    quit;
    proc sql;
    %do i = 1 %to &ank1;

    select distinct(filename) into :file1 - :file&ank1 from imptbase.data_manipulation;
    select max(sequence) into :mx from imptbase.data_manipulation where filename = "&&file&i";

    %let mx1 = %eval(&mx);

    select distinct(macroname) into :mac1 - :mac&mx1 from imptbase.data_manipulation where filename = "&&file&i";

    %put &file1 &file2 &mx &mac1 &mac2 &mac3;

    %do j = 1 %to &mx1;

    %&&mac&j;

    %end;

    %end;
    quit;
    %mend;

    Desired value of mac1 = inserted, mac2 = deleted, mac3 = dropped.
    But it is getting displayed in log as mac1 = deleted, mac2 = dropped, mac3 = inserted.

    problem with this code is value of macroname are getting sorted alphbetically(dont know why?)

    Can anybody plz help to get the desired output.

    Thanks in advance.

    ReplyDelete
  5. Hi Guys
    Could someone please tell me that a SAS Macro use PDV or not.
    If yes then in what circumstances because how much i know Macro facility does not have PDV.

    Deepanshu could you please add a page about this in SAS Macro section. If you could then i will be very much thankfull to you.

    ReplyDelete
    Replies
    1. Hi,
      I guess you are confusing yourself by comparing SAS PDV with SAS MACRO Processing, both are different.

      SAS PDV get created while data step processing while SAS macro gets processed by SAS macro processor.

      Delete
  6. Nice tutorial. Heowever, you mentioned %LET. Does it work?
    Thanks,
    Jeshwika

    ReplyDelete
    Replies
    1. It works. Please let me know if you face any issue(s) related to it.

      Delete
    2. Plz, can u give explanation about autocall macros.?

      Delete
  7. Hi Deepanshu,

    There is one mmore I know iss %window statement

    ReplyDelete
  8. I wish I had found this blog earlier! It's great. :)

    ReplyDelete
  9. Answer to exercise:
    proc sql;
    select count(distinct make) into :mk from sashelp.cars;
    quit;
    %put &mk.;
    %put %sysevalf(&mk.*2.5);

    ReplyDelete
  10. awesome blog man! keep it up!

    ReplyDelete
  11. HI ALl,
    i have below mentioned data.
    data tab1;
    input custid$ @6 saledate mmddyy10. @17 variety $9. @26 quantity ;
    format saledate mmddyy10.;
    datalines;
    240w 02-07-2003 ginger 120
    240w 02-07-2003 protea 180
    356w 02-08-2003 heliconia 60
    356w 02-08-2003 anthurium 300
    188r 02-11-2003 ginger 24
    188r 02-11-2003 anthurium 24
    240w 02-12-2003 heliconia 48
    240w 02-12-2003 protea 48
    356w 02-12-2003 'ginger' 240
    ;
    run;
    i made below macro for same.
    %macro new (flowertype=);
    proc print data=tab1;
    where variety ="&flowertype" & custid="&id";
    run;
    %mend;
    %new (flowertype=ginger);

    Can anyone tell me how to make macro of dates. Like i make flowertype and its ginger when i will mention any flowertype in macro then it will give me print. Same way i want to make macro of Date. if i will mention particular date then macro will show me the result of that date only.

    ReplyDelete
  12. This comment has been removed by the author.

    ReplyDelete
  13. This comment has been removed by the author.

    ReplyDelete
  14. Hello,

    I Have similar data like given in the following dataset. What i am trying to do is subset the data for each value of location.

    Data Test;
    Input Name$ Location$;
    cards;
    Jhon
    Mary
    Ann
    Alfred
    Bob
    Joe
    ;
    run;

    I have written the following macro.

    %macro Subset (Dset= ,var= );
    data &Dset;
    set &Dset;
    where Location=&var;
    run;
    %mend;

    Calling macro:

    %Subset(Dset=Test,var="");

    I understand that it will not work because of the spl char and to mask or remove the meaning of them we have to use %STR function.

    But I am not understanding where to use that %STR function.

    Can anyone help me please.

    Thank you so much.

    ReplyDelete
  15. This comment has been removed by the author.

    ReplyDelete
  16. Hello,

    I Have similar data like given in the following dataset. What i am trying to do is subset the data for each value of location.

    Data Test;
    Input Name$ Location$;
    cards;
    Data Test;
    Input Name$ Location$;
    cards;
    Jhon office
    Mary parlour
    Ann Bank
    Alfred office
    Bob Bank
    Joe Parlour
    ;
    run;

    The Location values are enclosed in< > like ex,

    I have written the following macro.

    %macro Subset (Dset= ,var= );
    data &Dset;
    set &Dset;
    where Location=&var;
    run;
    %mend;

    Calling macro:

    %Subset(Dset=Test,var="");

    I understand that it will not work because of the spl char and to mask or remove the meaning of them we have to use %STR function.

    But I am not understanding where to use that %STR function.

    Can anyone help me please.

    Thank you so much.

    ReplyDelete
    Replies
    1. YOU CAN ALSO USE THE FOLLOWING CODE :

      PROC SQL NOPRINT;
      SELECT DISTINCT LOCATION INTO: LOC SEPARATED BY ' '
      FROM TEST;
      QUIT;

      DATA &LOC;
      SET TEST;
      IF Location="%SCAN(&LOC,1,' ')" THEN OUTPUT %SCAN(&LOC,1,' ');
      ELSE IF Location ="%SCAN(&LOC,2,' ')" THEN OUTPUT %SCAN(&LOC,2,' ');
      ELSE IF Location="%SCAN(&LOC,3,' ')" THEN OUTPUT %SCAN(&LOC,3,' ');
      RUN;

      Delete
    2. the code which you have written must be like this :

      %macro Subset (Dset1=,Dset= ,var= );
      data &Dset1;
      set &Dset;
      where Location="&var";
      run;
      %mend;


      %Subset(Dset1=BANK1,Dset=Test,var=Bank);

      Delete
  17. The count is 95.

    ReplyDelete

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