Passing a Dynamic Variable from Data set as a Macro Parameter

[BadMojoNixon]

Hello everyone, I'm newish to SAS, so please bare with me. I'm trying to create multiple flag variables based on the contents of a parsed out variable. My macro isn't doing what I want it to do... it's parameter is passing as a static string, rather than a dynamic variable. Any help would be greatly appreciated.

-----------

Details!

This is my input data:

data Input;                                                                         
input Variable_source $15.;                          
datalines;                                                                          
01 03
01 03 04
01 05
01 02
;

Here is my Macro code

%macro parse (temp=);
	data output; set Input; 
		%local i;
		%do i = 1 %to %sysfunc(countw(&temp));
			%let code = %scan(&temp, &i, %str( ));
			VARIABLE_&code=1;
		%end;
	run;
%mend;

%parse (temp=Variable_source);

It gives me this:

Variable_source	VARIABLE_variable_source
01 03	1
01 03 04	1
01 05	1
01 02	1

But I want this:

Variable_source	VARIABLE_01	VARIABLE_02	VARIABLE_03	VARIABLE_04	VARIABLE_05
01 03	1		1
01 03 04	1		1	1
01 05	1				1
01 02	1	1

[CalleJ]

Hello!

The reason your macro doesn't work is because the macro is compiled before the data step is processed, i.e. the countw(&temp) will translate into countw(Variable_source) = 1 (same with the %scan()-function).

This is one way of doing it without using a macro:

data Input;                                                                         
input Variable_source $15.;                          
datalines;                                                                          
01 03
01 03 04
01 05
01 02
;

/* Looping through each dynamic array (using scan() to loop through the "words" and outputing each source as a new row) */
/* Creating dummy variable transpose_var=1 for transpose below and temporary variable rownumber to avoid sorting issues when transposing */
data work.input_spliced(drop=i);
	set work.input;
	rownumber = _n_;
	transpose_var = 1;
	do i = 1 to countw(Variable_source);
		Var_source_spliced = scan(Variable_source,i);
		output;
	end;
run;

/* Transposing the spliced table with variable prefix VARIABLE_ */
proc transpose data=work.input_spliced out=work.output(drop=rownumber _name_) prefix=VARIABLE_;
	by rownumber Variable_source;
	id Var_source_spliced;
	var transpose_var;
run;

Kind regards

/Calle

Edit: Realized there was some unnecessary code in there, so I trimmed the solution a bit. 🙂