topic finding consecutive different values across variables in SAS Programming

finding consecutive different values across variables

fama — Thu, 15 Jun 2017 13:52:45 GMT

Hi all,

I am pretty new in SAS programming and do need your help. thx

i have a data set like this ( 5 variabes and too many observations)

num a b c d e

1 . 3 4 . .

2 . 5 . 6 .

3 1 2 2 . .

4 2 . . . 4

desired result

num a b c d e

1 . 3 4 . .

2 1 2 2 . .

Indeed, i want to have just those rows that contain 2 consecutive different values.

i do appreciate your help

jdwaterman91 — Thu, 15 Jun 2017 15:23:57 GMT

This logic should give you your desired output.

/* Creating the dataset */

Data Input;
Input Num a b c d e ;
Datalines;
1 . 3 4 . .
2 . 5 . 6 .
3 1 2 2 . .
4 2 . . . 4
;
Run;

/* Eliminate rows that do not have consecutive non-missing values */

Data Final;
Set Input;
If Num ^= "" Then do;
If ( (b*a = "") and (c*b = "") and (d*c = "") and (e*d = ""))
Then Delete;
End;
Run;

Astounding — Thu, 15 Jun 2017 16:30:34 GMT

It's a little complex, since it uses arrays. But not too lengthy:

data want;

set have;

array vars {5} a b c d e;

do _n_=1 to 4;

if (vars{_n_} ne .) and (vars{_n_+1} ne .) and (vars{_n_} ne vars{_n_+1}) then keep_flag='Y';

end;

if keep_flag='Y';

drop keep_flag;

run;

fama — Fri, 16 Jun 2017 00:20:47 GMT

it worked well. really appreciate it.

thanks 🙂

fama — Fri, 16 Jun 2017 00:41:36 GMT

Thanks for your help. it did not work. still shows undesired observations.

jdwaterman91 — Fri, 16 Jun 2017 12:59:32 GMT

I'm sorry that did not work.

Just out of curiousity, what is an example of an undesired row that was showing up in your output?

I will say that the array method in the post below is a better way of approaching the problem compared to what I did.