topic Re: Coding Help in SAS Programming

Coding Help

mounikag — Thu, 04 Mar 2021 21:26:53 GMT

Hi Team,

data x;
infile;
datalines;
subj astdt(NUm) inj1(char) inj2(char) inj3(char) inj4(char) No.of injs before astdt
101 2020-06-03 2019-07-18 2019-08-15 2019-09-10 2019-11-14 4
102 2019-08-07 2019-06-12 2019-07-08 2019-08-12 2019-09-30 2
103 2020-01-09 2019-11-13 2019-12-16 2020-01-08 2020-03-04 3
104 2019-12-13 2019-11-13 2019-12-16 2020-01-08 2020-03-04 1
105 2019-05-15 2019-05-13 1
106 2019-08-05 2019-07-17 2019-08-14 1
107 2019-08-21 2019-07-17 2019-08-14 2
108 2020-06-30 2020-05-27 2020-06-24 2020-07-22 3
;
run;

I have data as above so, I would like to have help in coding.
I have four injections(inj1, inj2, inj3, inj4)which is in character format and i have astdt(ae start date) in numeric format.
i would like to know number of prior injections before astdt for each subject.
so, it should count the number of injections(non-missing injs) prior to the astdt.
please provide me a code it would be helpful .Thanks in advance.

Best,
Mounika.

Re: Coding Help

qoit — Thu, 04 Mar 2021 22:19:29 GMT

Below should do it:

data have;
	infile datalines missover truncover;
	input subj $ astdt yymmdd10. inj1 $11. inj2 $11. inj3 $11. inj4 $11.;
	format astdt date9.;
	datalines;
101 2020-06-03 2019-07-18 2019-08-15 2019-09-10 2019-11-14
102 2019-08-07 2019-06-12 2019-07-08 2019-08-12 2019-09-30
103 2020-01-09 2019-11-13 2019-12-16 2020-01-08 2020-03-04
104 2019-12-13 2019-11-13 2019-12-16 2020-01-08 2020-03-04
105 2019-05-15 2019-05-13                                 
106 2019-08-05 2019-07-17 2019-08-14                      
107 2019-08-21 2019-07-17 2019-08-14                      
108 2020-06-30 2020-05-27 2020-06-24 2020-07-22           
;
run;

data want;
	set have;
	array inj{4} $;
	array cnt{4};

	do i = 1 to dim(inj);
		if input(inj{i},yymmdd10.) < astdt and ^missing(inj{i}) then
			cnt{i} = 1;
		else cnt{i} = 0;
	end;

	total = sum(of cnt1 - cnt4);
	drop cnt1 - cnt4 i;
run;

Re: Coding Help

LeonidBatkhan — Thu, 04 Mar 2021 22:23:54 GMT

Hi mounikag,

You can do it using the following approach:

data x;
   length subj astdt 8 inj1-inj4 $10;
   infile datalines truncover;
   input subj astdt yymmdd10. inj1-inj4 $;
   format astdt yymmdd10.;
   datalines;
101 2020-06-03    2019-07-18     2019-08-15     2019-09-10     2019-11-14
102 2019-08-07    2019-06-12     2019-07-08     2019-08-12     2019-09-30
103 2020-01-09    2019-11-13     2019-12-16     2020-01-08     2020-03-04
104 2019-12-13    2019-11-13     2019-12-16     2020-01-08     2020-03-04  
105 2019-05-15    2019-05-13
106 2019-08-05    2019-07-17     2019-08-14 
107 2019-08-21    2019-07-17     2019-08-14 
108 2020-06-30    2020-05-27     2020-06-24     2020-07-22
;

DATA WANT;
   set x;
   array inj $ inj1-inj4;
   array injn injn1-injn4;
   no_injs_before_astdt = 0;
   do i=1 to dim(inj);
      injn[i] = input(inj[i],yymmdd10.);
      no_injs_before_astdt + (astdt > injn[i] > .);
   end;
run;

You can drop any variables you don't like to keep. Also, in your data last line you have an error, No.of injs before astdt should be equal 2, not 3.

This code essentially converts you character dates into numeric, and then loops through array elements and increments no_injs_before_astdt every time when (astdt > injn[i] > .)

Hope, this helps.

Re: Coding Help

mkeintz — Thu, 04 Mar 2021 22:58:03 GMT

If your INJ values are really arranged as

All actual dates are to the left (i.e. missing dates are always on the right)
INJ dates are in ascending order

Then you can use a WHILE expression and/or a leave statement to stop the loop - you don't always have to go from 1 to dim(INJ):

data have;
	infile datalines missover truncover;
	input subj $ astdt yymmdd10. inj1 $11. inj2 $11. inj3 $11. inj4 $11.;
	format astdt date9.;
	datalines;
101 2020-06-03 2019-07-18 2019-08-15 2019-09-10 2019-11-14
102 2019-08-07 2019-06-12 2019-07-08 2019-08-12 2019-09-30
103 2020-01-09 2019-11-13 2019-12-16 2020-01-08 2020-03-04
104 2019-12-13 2019-11-13 2019-12-16 2020-01-08 2020-03-04
105 2019-05-15 2019-05-13                                 
106 2019-08-05 2019-07-17 2019-08-14                      
107 2019-08-21 2019-07-17 2019-08-14                      
108 2020-06-30 2020-05-27 2020-06-24 2020-07-22           
;
run;

data want (drop=i);
	set have;
	array inj  $ inj: ;

	do i = 1 to dim(inj) while (inj{i}^=' ');
      if input(inj{i},yymmdd10.)<astdt then total=sum(total,1);
      else leave;
	end;
run;

Even more compact, but likely more obtuse:

data want (rename=(i=total));
  set have;
  array inj $ inj: ;
  do i=0 to dim(inj)-1 while (input(inj{i+1},yymmdd10.)<astdt and inj{i+1}^=' ');
  end;
run;