CODEWITHSUNDEEP
sassurvival-analysis
Econometrics33
Econometrics33

Reputation: 101

Create variable conditional on last and current observation variables values

Based on the simplified dataset below, I would like to create a new variable X3 that is equal to 1 if the last observation by variable id has default = 1 and if X1 = X2, else X3 = 0. 

data example;
    input id default X1 X2;
    cards;
    1 0 0 1
    1 0 0 1
    1 0 1 1
    1 0 0 1
    1 1 0 1
    2 0 0 1
    2 0 1 1
    2 0 0 1
    2 0 0 1
    2 1 0 1
    3 0 0 1
    3 0 1 1
    ;
run;

The new dataset should look like the following: 

id default X1 X2 X3;
1 0 0 1 0
1 0 0 1 0
1 0 1 1 1
1 0 0 1 0
1 1 0 1 0
2 0 0 1 0
2 0 1 1 1
2 0 0 1 0
2 0 0 1 0
2 1 0 1 0
3 0 0 1 0
3 0 0 1 0

I've tried quite a few things and have been unable to find any solutions. Any suggestions would be greatly appreciated!

Upvotes: 0

Views: 76

Answers (1)

user667489
user667489

Reputation: 9569

Double DOW-loop is the way to go here:

data want;
do _n_ = 1 by 1 until (last.ID);
  set example;
  by ID;
  if last.ID and default = 1 then last_default = 1;
  drop last_default;
end;
do _n_ = 1 to _n_;
  set example;
  x3 = x1 = x2 and last_default;
  output;
end;
run;

Upvotes: 0

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