计算SAS中观测值的总组合

Question

I have a variable with few values for that. Example: Var1 A,B,C,D,E,F,G,H

How can i find the total 2 letter combinations possible? eg: AB, AC, AD etc.

Here the list i have mentioned is small but in general I have a huge list and need to find total two letter combinations possible with all the values present for the variable. Thanks

Answer 1

A Cartesian join will give you every combination against every combination, so a self join here will give you all possibilities. I usually use Proc SQL:

 Proc sql;
    create table cartesian1 as
        select * from table1,table1;
 Quit;

Answer 2

Does this give you the table you want? I'm assuming that you want all 2 letter combinations rather than permutations (ie order is not relevant).

data have;
input var1 $;
datalines;
A
B
C
D
E
F
G
H
;
run;

data want;
set have nobs=nobs;
length two_way $2;
do i=_n_+1 to nobs;
    set have (rename=(var1=temp)) point=i;
two_way=cats(var1,temp);
keep two_way;
output;
end;
run;