DATA HAVE :
ID | Q01 | Q02 | Q03 | Q04 | FIRST_ANSWERED |
1 | NULL | NULL | NULL | NULL | 0 |
1 | NULL | 7 | NULL | NULL | 1 |
1 | NULL | 8 | 9 | 6 | 0 |
1 | 3 | 4 | 5 | 6 | 0 |
2 | NULL | NULL | NULL | NULL | 0 |
2 | 3 | 8 | 9 | 2 | 1 |
2 | 6 | 7 | 8 | 0 | 0 |
2 | 4 | 5 | 0 | 2 | 0 |
3 | NULL | NULL | NULL | NULL | 0 |
3 | 4 | 5 | 2 | NULL | 1 |
3 | 2 | 3 | 8 | 9 | 0 |
3 | 2 | 3 | 8 | 2 | 0 |
4 | 3 | 8 | 9 | 2 | 1 |
4 | 6 | 5 | 4 | 5 | 0 |
4 | 6 | 3 | 8 | 9 | 0 |
4 | NULL | NULL | NULL | NULL | 0 |
4 | 3 | 8 | 9 | 7 | 0 |
WANT TO ADD COLUMN "FIRST_ANSWERED", this column is labeling the first row by ID that Q1- Q4 are not all "NULL" as 1, otherwise as 0.
Thank you for your help.
Conversely, if you showed NULL merely to represent missing values, then you might be able to use something like:
DATA HAVE ;
input ID Q01-Q04;
cards;
1 . . . .
1 . 7 . .
1 . 8 9 6
1 3 4 5 6
2 . . . .
2 3 8 9 2
2 6 7 8 0
2 4 5 0 2
3 . . . .
3 4 5 2 .
3 2 3 8 9
3 2 3 8 2
4 3 8 9 2
4 6 5 4 5
4 6 3 8 9
4 . . . .
4 3 8 9 7
;
run;
data want (drop=flag_set);
set have;
retain flag_set;
by id;
if first.id then flag_set=0;
first_answered=not flag_set and sum(of q01-q04) gt 0;
if first_answered then flag_set=1;
run;
Here's one solution, I'm sure there are others...I use a flag to keep track of when the first answered is set and reset at the first of every ID.
DATA HAVE ;
input ID Q01 $ Q02 $ Q03 $ Q04 $ FIRST_ANSWERED;
cards;
1 NULL NULL NULL NULL 0
1 NULL 7 NULL NULL 1
1 NULL 8 9 6 0
1 3 4 5 6 0
2 NULL NULL NULL NULL 0
2 3 8 9 2 1
2 6 7 8 0 0
2 4 5 0 2 0
3 NULL NULL NULL NULL 0
3 4 5 2 NULL 1
3 2 3 8 9 0
3 2 3 8 2 0
4 3 8 9 2 1
4 6 5 4 5 0
4 6 3 8 9 0
4 NULL NULL NULL NULL 0
4 3 8 9 7 0
;
run;
data want;
set have;
retain flag_set;
by id;
if first.id then flag_set=0;
first_answered2=0;
if compress(tranwrd(catt(of Q01-Q04), "NULL", "")) ne "" and flag_set=0 then do;
first_answered2=1;
flag_set=1;;
end;
run;
Conversely, if you showed NULL merely to represent missing values, then you might be able to use something like:
DATA HAVE ;
input ID Q01-Q04;
cards;
1 . . . .
1 . 7 . .
1 . 8 9 6
1 3 4 5 6
2 . . . .
2 3 8 9 2
2 6 7 8 0
2 4 5 0 2
3 . . . .
3 4 5 2 .
3 2 3 8 9
3 2 3 8 2
4 3 8 9 2
4 6 5 4 5
4 6 3 8 9
4 . . . .
4 3 8 9 7
;
run;
data want (drop=flag_set);
set have;
retain flag_set;
by id;
if first.id then flag_set=0;
first_answered=not flag_set and sum(of q01-q04) gt 0;
if first_answered then flag_set=1;
run;
Thank you so much. This is great!!!
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