concatenate multiple variables

[ykcgod]

Hi all, 

I would like to concatenate multiple subject IDs that looks like this:

S002001~S002002, S002006~S002012, S002014~S002016

so basically, I would like to connect the subjid's that are continuous with "~" and use "," for those that is not continuous..

here's the data:

data a;
input subjid $8.;
cards;
S002001
S002002
S002006
S002007
S002008
S002009
S002010
S002011
S002012
S002014
S002015
S002016
;
run;

Thanks in advance for your help!

[PeterClemmensen]

Are all your values prefixed by "S"?

[andreas_lds]

Do you want that list in saved in a dataset-variable? Can you describe what the next steps are?

[s_lassen · Accepted solution]

I think the easiest way is to start with creating a group variable:

Data grouped;
  set a;
  _number=input(substr(subjid,2),6.);
  if dif(_number) ne 1 then
    group+1;
  drop _number;
run;

Then you can use CATX to create the string:

Data want;
  set grouped end=done;
  by group;
  length Sequences $200;
  retain Sequences;
  if first.group then 
    call catx(', ',Sequences,subjid);
  else if last.group then 
    call catx('~',Sequences,subjid);
  if done;
  keep Sequences;
run;

[ykcgod]

Yess! This will do. Thanks so much for your help!