topic Re: Macro and array loop in SAS Programming

Macro and array loop

sonic_poem — Thu, 23 May 2019 19:08:28 GMT

I have character variables pt1-pt&review (the maximum ranges vary). I'm trying to find out if there is a match to main variable allpt for each of these variables by using index function for all the rows (first.id to last.id) in the dataset. If matched, the array variables check1-check&review will have value>0. Since I need to use the value of the variables pt1-pt34 for index function, I tried using macro function "call symputx..." I'm getting error messages with the codes below.

data tagged;
length id $ 8 check1-check&review 8;
do until (last.id);
set case;
by id;
array pt(&review) $;
array check(&review) $;
do i = 1 to dim(check);
call symputx ('name', pt[i]);
check[i] = index (allpt,'&name');
end;
drop i;
run;

ERROR 22-322: Syntax error, expecting one of the following: a name, _ALL_, _CHARACTER_, _CHAR_,
_NUMERIC_.

ERROR: Missing numeric suffix on a numbered variable list (check1-check).
ERROR 352-185: The length of numeric variables is 3-8.

Macro variable REVIEW resolved successfully, by the way.

Thanks for help!

Re: Macro and array loop

Kurt_Bremser — Thu, 23 May 2019 19:16:45 GMT

If macro variable &review has leading blanks, it won't work.

Either change how you set it, or add

%let review=&review.;

to remove the blanks.

Re: Macro and array loop

Tom — Thu, 23 May 2019 19:34:18 GMT

How did you create the macro variable REVIEW?

If you are using PROC SQL with the INTO clause then make sure to use the TRIMMED keyword to remove leading spaces.

proc sql noprint;
select max(review_number) into :review TRIMMED 
from mydata;
quit;

You could also use %LET to remove unquoted spaces.

%let review=&review ;

Or modify your program so that leading spaces don't impact it. For example set the length of CHECK1 to CHECK8 using the ARRAY statement. Also make you your mind whether CHECK1 to CHECK8 are numeric or character. Your LENGTH statement defines them as numeric put you included a $ in your array statement. Assuming you want them as character:

data tagged;
  length id $8 ;
  array check(&review) $8;

Re: Macro and array loop

sonic_poem — Fri, 24 May 2019 11:23:56 GMT

Thanks for the feed back. I tried the methods suggested. I also tried using numeric version of review (as reviewn) to see if it helps.

proc sql;

select count as observation

into: review TRIMMED

from high;

quit;

%let review=&review;

%let reviewn=%eval(&review);

Good thing is using either REVIEW or REVIEWN, I no longer get any error messages. However, all my CHECK variables are 0 using the program below. I believe CHECK should be a numeric variable since it's an output from the INDEX function. I have modified the code as suggested. I am also uploading the sample data and the output I would like to see when the program runs successfully.

proc sort data=case3;by id;run;

data tagged;

length id $ 8 check1-check&review 8;

do until (last.id);

set case3;

by id;

array pt(&review) $;

array check(&review) ;

do i = 1 to dim(check);

call symputx ('name', pt[i]);

check[i] = index (PTUPC,'&name');

end;

drop i;

run;

id	pt1	pt2	pt3	allpt	ck1	ck2	ck3
a001	ab	ab	ac	abd	1	1	0
a002	ac	ab	dc	abd	0	1	0
a003	ad	ab	bd	abd	0	1	2

Re: Macro and array loop

Kurt_Bremser — Fri, 24 May 2019 11:40:59 GMT

This

call symputx ('name', pt[i]);
check[i] = index (PTUPC,'&name');

cannot work, for two reasons:

macro triggers are not resolved when enclosed in single quotes, one must use double quotes.
but the more important: the macro reference will be resolved while the data step is compiled, but call symput() is executed when the data step runs.

Why don't you just do

check[i] = index(PTUPC,strip(pt[i]));

Re: Macro and array loop

sonic_poem — Fri, 24 May 2019 12:05:07 GMT

The corrected version below is working. Thank you!

data tagged;

length id $ 8 check1-check&reviewn 8;

do until (last.id);

set case3;

by id;

array pt(&reviewn) $;

array check(&reviewn) ;

do i = 1 to dim(check);

check[i] = index(PTUPC,strip(pt[i]));

end;

drop i;

run;