topic Re: differen value within second by variable in SAS Programming

differen value within second by variable

SASSLICK001 — Thu, 30 Aug 2018 15:33:47 GMT

Hi I have the following

id1 id2

01 1

01 2

02 1

How can I ideintify the different value id2 within id1?

Re: differen value within second by variable

Astounding — Thu, 30 Aug 2018 15:43:09 GMT

This both identifies and counts for you:

proc freq data=have;

tables id1 * id2 / list missing;

run;

Re: differen value within second by variable

SASSLICK001 — Thu, 30 Aug 2018 18:54:26 GMT

I wanted to use first. and last.

Re: differen value within second by variable

ballardw — Thu, 30 Aug 2018 19:50:06 GMT

@SASSLICK001 wrote:
I wanted to use first. and last.

It would help to show what you expect for output.

Maybe something like ?

data want;
   set have;
   by id1 id2;
   if first.id2;
run;

Re: differen value within second by variable

SASSLICK001 — Fri, 31 Aug 2018 16:23:20 GMT

I want to create a flag where the value changes per change in value for id2

expected output

id1 id2 flag

01 x 1

01 y 2

02 z 1

Re: differen value within second by variable

ballardw — Fri, 31 Aug 2018 17:21:26 GMT

Assuming your data is sorted by ID1 and ID2 as implied by your example:

data have;
input id1 $ id2  $;
datalines;
01  x 
01  x 
01  y 
02  z 
02  z 
02  z 
;
run;
data want;
   set have;
   by id1 id2;
   if first.id1 then flag=0;
   else flag = first.id2;
run;

I prefer the 0/1 coding as 0 means 'not a change' in this case and there are some advantages that I can count the number of changes in id1 by getting a sum of the flag variable.

If your data is not sorted then you need to provide a more realistic example of the data.

Re: differen value within second by variable

Astounding — Fri, 31 Aug 2018 20:25:13 GMT

For that result:

proc sort data=have;

by id1 id2;

run;

data want;

set have;

by id1 id2;

if first.id1 then flag=1;

else if first.id2 then flag + 1;

run;