topic Re: Get the combinations with do loop in SAS Programming

Get the combinations with do loop

sas_newbie3 — Tue, 14 Mar 2017 20:50:53 GMT

Say we have 4 letters--"A", "B","C","D". Now I want to get the combinations, the result should be 16 ELEMENTS.

AA
AB
AC
AD
BA
BB
BC
BD
CA
CB
CC
CD
DA
DB
DC
DD

Thank you.

Re: Get the combinations with do loop

collinelliot — Tue, 14 Mar 2017 20:55:17 GMT

data want;
do i = 'A', 'B', 'C', 'D';
do j = 'A', 'B', 'C', 'D';
var = cats(i, j);
output;
end;
end;
run;

Re: Get the combinations with do loop

sas_newbie3 — Tue, 14 Mar 2017 22:14:03 GMT

Hi,

I want the result can be an arrary format, so I can retrieve the first element and second item etc.

So for example, for AA, it is an array. The first item of the array is A, the second item of array is A also.

Re: Get the combinations with do loop

collinelliot — Tue, 14 Mar 2017 22:52:10 GMT

I'm really sorry, but I don't understand. The code I provided gives you the results you specified. The i and j give you the two separate portions, if that's what you mean.

Re: Get the combinations with do loop

art297 — Tue, 14 Mar 2017 23:17:10 GMT

Not sure what you're asking for. Is it something like:

data want (keep=first: second:);
  array first(16) $;
  array second(16) $;
  do i = 'A', 'B', 'C', 'D';
    do j = 'A', 'B', 'C', 'D';
      cell+1;
      first(cell)=i;
      second(cell)=j ;
    end;
  end;
run;

Art, CEO, AnalystFinder.com

Re: Get the combinations with do loop

ballardw — Tue, 14 Mar 2017 23:32:13 GMT

@sas_newbie3 wrote:

Hi,

I want the result can be an arrary format, so I can retrieve the first element and second item etc.

So for example, for AA, it is an array. The first item of the array is A, the second item of array is A also.

Then go back to your orginal post and change the "example" data to what you actually want. Your example implied one record per two character concatenated string.

And your description would result in 32 values not 16:

A,A,A,B,A,C,A,D,B,A,B,B,B,C,B,D,C,A,C,B,C,C,C,D,D,A,D,B,D,C,D,D

data junk;
   array x {32} $1.;
   counter=0;
   do i= 'A','B','C','D';
      do j= 'A','B','C','D';
         counter+1;
         x[counter]=i ;
         counter+1;
         x[counter]=j ;
      end;
   end;
   output;
   drop counter i j;
run;