squaring vales then adding squares by group

[Ihsan-Mahdi]

Hello,

I have a data set that looks something like this:

DATA example;
INPUT id ais;
DATALINES;
1 3
1 4
2 5
2 7
2 3
3 2
3 4
3 1
;
run;

I would like to square each "ais" value, then add the squares by each "id" value creating a new variable called "iss".

so for "id" (1) the iss should equal 9+16=25.

I tried different codes but none worked. Help please!

[PaigeMiller]

This is a job for PROC SUMMARY. No need to write your own DATA step code with a mathematical formula.

proc summary data=example nway;
    class id;
    var ais;
    output out=want uss=sum_of_squares;
run;

[Ihsan-Mahdi]

Thank you!

[Tom · Accepted solution]

Assuming you want to output 3 observations, one per BY group, then something like this should do the job.

data want;
  do until(last.id);
    set example;
    by id;
    iss = sum(iss,ais**2);
  end;
  keep id iss;
run;