topic Re: Creating combinations of items in the list in SAS Programming

Creating combinations of items in the list

Lucas — Fri, 28 Aug 2015 11:42:16 GMT

Hello,

I have a list of variables:

data tab;

input var $;

datalines;

;

I need to create unique combinations of these variables:

A
A	B
A	B	C
A	C
B
B	C
C

Thank you in advance for your help.

Re: Creating combinations of items in the list

RW9 — Fri, 28 Aug 2015 12:04:49 GMT

Hi,

Something like:

data tab;

input var $;

datalines;

;

run;

proc transpose data=tab out=ttab;

var var;

run;

data want (keep=var1-var3);

set ttab;

length var1 var2 var3 $1;

array col{3};

array var{3};

do i=1 to 3;

var1=col{i};

output;

do j=i+1 to 3;

var{j}=col{j};

output;

end;

var1=""; var2=""; var3="";

end;

run;

Re: Creating combinations of items in the list

Lucas — Fri, 28 Aug 2015 12:17:24 GMT

Hi,

thank you for quick response.

I used your code but one combination is missing (A C)

Re: Creating combinations of items in the list

RW9 — Fri, 28 Aug 2015 12:24:55 GMT

Got a meeting now, will try to look later. I had got to this, needs sorting of the characters and then nodupkey sort:

data tab;

infile datalines missover;

input var $;

datalines;

;

run;

proc sql;

create table WANT as

select A.VAR as VAR1,

B.VAR as VAR2,

C.VAR as VAR3

from TAB A

full join TAB B

on A.VAR ne B.VAR

full join TAB C

on A.VAR ne C.VAR

and B.VAR ne C.VAR

union all

select VAR as VAR1,

"" as VAR2,

"" as VAR3

from TAB ;

quit;

Re: Creating combinations of items in the list

Ksharp — Fri, 28 Aug 2015 12:37:28 GMT

The simplest way is using proc means . Otherwise if you consider about efficient, then using GRAYCODE().

Code: Program

data tab;
input var $;
datalines;
A
B
C
;
run;
proc transpose data=tab out=temp(drop=_name_);
 var var;
run;
proc summary data=temp;
class col:;
output out=want(where=(_type_ ne 0));
run;

Xia Keshan