Create new ID starting from 1

[trungdungtran]

Hi all,

I have a longitudinal data where each subject has a number of repeated measurements, i.e., occupying several rows in the data table. Unfortunately, the ID is not starting from 1. Now I would like to create a new ID, starting from 1. I have completed a SAS code as follows:

data original;
input   ID  ;
cards;
12
12
12
16
16
19
19
19
27
27
27
;
run;

data newID;
      set original;
      retain newID 1 previousID 12;
      if ID=previousID then newID=newID;
      else newID=newID+1;
      previousID=ID;
	  drop previousID;
run;

Proc print data=newID noobs;
run;

This code works as I want. However, I feel the code complicated. Do you have any suggestion to make it simpler?

Thank you for reading!

[ballardw · Accepted solution]

---

@trungdungtran wrote:

Hi all,

I have a longitudinal data where each subject has a number of repeated measurements, i.e., occupying several rows in the data table. Unfortunately, the ID is not starting from 1. Now I would like to create a new ID, starting from 1. I have completed a SAS code as follows:

data original;
input   ID  ;
cards;
12
12
12
16
16
19
19
19
27
27
27
;
run;

data newID;
      set original;
      retain newID 1 previousID 12;
      if ID=previousID then newID=newID;
      else newID=newID+1;
      previousID=ID;
	  drop previousID;
run;

Proc print data=newID noobs;
run;

This code works as I want. However, I feel the code complicated. Do you have any suggestion to make it simpler?

Thank you for reading!

---

Something like this maybe?

data have;
input   ID  ;
cards;
12
12
12
16
16
19
19
19
27
27
27
;
run;
proc sort data=have;
  by id;
run;

data want;
   set have;
   by id;
   if first.id then Newid+1;
run;

I explicitly sorted the data by ID just in case and so that all of the values of ID end up with the same newid.