topic remove duplicated pairs of variable values in SAS Programming

remove duplicated pairs of variable values

somebody — Thu, 07 Dec 2017 10:15:18 GMT

I would like to remove observations where the value in 2 columns are the same (exists before). For example, pair A and B exist already so I would like to remove the fourth observation. similarly, I would like to remove the last obs as the pair B and C already exist.

student1	student2	treatment
A	B	keep
A	C	keep
A	D	keep
B	A	remove
B	C	keep
B	D	keep
C	A	keep
C	B	remove

Re: remove duplicated pairs of variable values

s_lassen — Thu, 07 Dec 2017 10:28:07 GMT

If you can live with an arbitrary order of your students in the rows, you can use SORTC to get the students in the same order everywhere. Then it is just a question of removing the duplicates (SORT with NODUPKEY):

data sorted;
  set have;
  call sortc(student1,student2);
run;

proc sort nodupkey;
  by student1 student2;
run;

Re: remove duplicated pairs of variable values

RW9 — Thu, 07 Dec 2017 10:28:25 GMT

!!!Post test data in the form of a datastep using the code window which is the {i} above post!!!

data have;
  input student1 $ student2 $;
datalines;
A B
A C
A D
B A
B C
B D
;
run;

data want;
  set have;
  array student{2};
  call sortc(of student{*});
run;

proc sort data=want nodupkey;
  by student:;
run;