topic Re: Countw within a macro in SAS Programming

Countw within a macro

MeganE — Thu, 15 Sep 2016 15:12:19 GMT

Hi,

I saw a couple of other posts on countw within a macro, but none addressed what i'm seeing.

I've inherited code, and i understand what it's doing (added commas between the list of words), but i keep getting errors when i try to run it. Don't ask why one macro variable is another macro variable that holds the list. I havent' gotten that far in cleaning it up yet...

%let _mClist    = PROVHCFA seq_keyc HCFASAF DISCSTAT PDGNS_CD;          *define variables of interest;

%macro test (varList = &_mClist);
   %put _mClist    = &varList;              *define variables of interest;
   %let _mSelectedVar =;
   %do i = 1 %to %sysfunc(countw(&varList.));
           %if &i < %sysfunc(countw(&varList.)) %then
                  %let _mSelectedVar = &_mSelectedVar %scan(&varList,%eval(&i)),;   /*if < 5 then _mSelectedVar = _mSelectedVar + a comma*/
           %else %let _mSelectedVar = &_mSelectedVar %scan(&varList,%eval(&i));   /*if last variable (ie, 5 < 5 will be false), then just _mSelectedVar, no comma*/
   %end;
%mend;
%test (varlist=);

When i run that, the log says:

ERROR: The function COUNTW referenced by the %SYSFUNC or %QSYSFUNC macro function has too few
arguments.
ERROR: A character operand was found in the %EVAL function or %IF condition where a numeric
operand is required. The condition was: %sysfunc(countw(&varList.))
ERROR: The %TO value of the %DO I loop is invalid.
ERROR: The macro TEST will stop executing.

But i've seen countw with just a single macro input before, so i dont' know what it thinks is missing.

So then i replaced the macro variable with the actual variable list, and i get this in the log after each cycle:

ERROR: The function COUNTW referenced by the %SYSFUNC or %QSYSFUNC macro function has too few
arguments.

Any ideas?

Thanks,
Megan

Re: Countw within a macro

MeganE — Thu, 15 Sep 2016 15:19:36 GMT

So, messing around with it still, i removed the input macro reference on the %macro line, and set it up as a %let instead for testing, and it ran without error. I changed nothing else.

So the code works now, but if someone knows WHY!?!?!?!?!?!?, that would be incredibly helpful. 🙂

%let varlist    = PROVHCFA seq_keyc HCFASAF DISCSTAT PDGNS_CD;          *define variables of interest;

%macro test;
   %put _mClist    = &varList;              *define variables of interest;
   %let _mSelectedVar =;
   %let end=%sysfunc(countw(&varList.));
   %do i = 1 %to &end.;
           %if &i < %sysfunc(countw(&varList.)) %then
                  %let _mSelectedVar = &_mSelectedVar %scan(&varList,%eval(&i)),;   /*if 1 < 5 then _mSelectedVar = _mSelectedVar + a comma*/
           %else %let _mSelectedVar = &_mSelectedVar %scan(&varList,%eval(&i));   /*if last variable (ie, 5 < 5 will be false), then just _mSelectedVar, no comma*/
   %end;
%mend;
%test;

Re: Countw within a macro

Loko — Thu, 15 Sep 2016 15:21:01 GMT

hello,

when you call the macro like you do - %test (varlist=); you set the value of the macro variable varlist to blank.

if you want it to have the value of _mClist, call the macro: %test ();

Re: Countw within a macro

MeganE — Thu, 15 Sep 2016 15:23:55 GMT

I dont' know what you mean. When it wasn't working, varlist was called another macro:
(varList = &_mClist)

Re: Countw within a macro

ballardw — Thu, 15 Sep 2016 15:53:49 GMT

HOW are you actually attempting to use this macro? I do not see how anything sees the result of this this variable unless you are dangerously expecting a global macro variable _mSelectedVar to exist before calling the macro.

And what was the value of &_mClist when the error occurs.

You might want to set Option Mprint Symbolgen; then re-run the code and show us the log.

Re: Countw within a macro

MeganE — Thu, 15 Sep 2016 15:55:28 GMT

I didn't write the code, i'm just trying to recreate it. It builds a list of variables that don't have commas, with commas, so they can be used in a proc sql step a bit further on. I got it to run though, thanks.

Re: Countw within a macro

Astounding — Thu, 15 Sep 2016 16:28:03 GMT

Megan,

Loko actually gave you the correct answer. Look at the difference between the macro call that didn't work, vs. the one that did work.

%test (varlist=); /* did not work */

%test; /* did work */

The first macro call uses the macro but overrides the default value for &VARLIST, giving it a null value. The second macro call uses the default value for &VARLIST from when the macro was defined.

COUNTW will have trouble when it encounters a null value for &VARLIST.

Finally, note that you may not need this macro at all. The IN operator in a WHERE clause does not require commas to separate values. Spaces are usually fine.

Re: Countw within a macro

MeganE — Thu, 15 Sep 2016 16:30:00 GMT

As far as i know, you can't separate variables in the select statement of proc sql without commas. That's where this string is being used.

Re: Countw within a macro

Astounding — Thu, 15 Sep 2016 16:32:09 GMT

You're right about that. I was picturing values of a variable. The variable names require the commas.