topic Re: Dynamic LENGTH? in SAS Programming

Dynamic LENGTH?

texasmfp — Tue, 22 Oct 2019 02:57:28 GMT

Hi:

I am trying to set a length based on a calculated value.

For example, if I read in 36 variables of 6 characters/variable and, concatenate those to a new variable that has a total length of 216. Now the default is 200 characters, so I will get a truncation message. Easily solved by setting a length

length concatvar $ 216;

However, if change the input to just 30 variables of 6 characters each, and concatenate, the new variable is 180 characters. If the length had previously been set at 216, that would leave blanks. And, if I ran it a third time concatenating 50 variables, that is a length of 300.

Is it possible to avoid manually calculating and setting the length; making it dynamic, based on a calculated number (i.e., length concatvar $ (calculated number)?

Re: Dynamic LENGTH?

ed_sas_member — Tue, 22 Oct 2019 04:41:30 GMT

You can try the code below ad then use the macrovariable &total_length in a length statement in a data step.

%let list_var = /* list your variables. E.g. var1 var2 var3 var4 */;

data _Null_;
	set sample; /*specify your dataset*/
	array variables(*) $ &list_var ;
	do i=1 to dim(variables);
		total_lenght + length(variables(i));
	end;
	call symputx("total_length",total_lenght);
run;

 
data want;
	set sample;
	length new_var $ &total_length;
	....;
run;

Re: Dynamic LENGTH?

Kurt_Bremser — Tue, 22 Oct 2019 05:52:33 GMT

You can get the defined length of a variable from dictionary.columns in proc sql.

So you can run this

proc sql noprint;
select sum(length) into :concat_length
from dictionary.columns
where libname = 'XXX' and memname = 'YYY' and /* insert condition to identify your character columns here */;
quit;

to later use &concat_length in your code.

Re: Dynamic LENGTH?

texasmfp — Thu, 24 Oct 2019 01:41:54 GMT

I solved it using eval. Thanks all