Identifying duplicates across multiple variables

[BayzidurRahman]

Hi,

I have 4 variables as var1…var4. I want to identify the observations where same value occurs in more than 1 variable and then keep the value at it’s first occurrence.

For example,

The dataset I have:

Var1 var2 var3 var4

1          2          3          4

0          0          4          9

1          1          1          20

0          1          2          2

1          0          2          1

5          9          9          9

3          3          3          3         

The dataset I want:

Var1 var2 var3 var4

1          2          3          4

0          .           4          9

1          1          .           20

0          1          2          .

1          0          2          .

5          9          .           .

3          .           .           .

[JosvanderVelden]

The logic you want to implement is not clear since the second observation doesn't follow the guidelines you describe. In that observation you have two '1's! If I understand your guidelines the second observation should be 1 . . 20. Can you explain why that is not the case?

[BayzidurRahman]

Yes- you are right. it is about the 3rd observation

The dataset I want:

Var1 var2 var3 var4

1          2          3          4

0          .           4          9

1          .          .           20

0          1          2          .

1          0          2          .

5          9          .           .

3          .           .           .

[Ksharp · Accepted solution]

data have;
input Var1 var2 var3 var4;
cards;
1          2          3          4
0          0          4          9
1          1          1          20
0          1          2          2
1          0          2          1
5          9          9          9
3          3          3          3      
;

data want;
 set have;
 array v{*} var1-var4;
 array x{*} x1-x4;
 do i=1 to dim(v);
  if v{i} not in x then x{i}=v{i};
   else v{i}=.;
 end;
 keep var1-var4;
run;

[BayzidurRahman]

Thanks very much.