topic Re: How to get all possible multiplicative interactions in SAS Programming

How to get all possible multiplicative interactions

deleted_user — Tue, 23 Dec 2008 06:26:34 GMT

Hi all,

I want to get all possible multiplicative interactions i.e, my input variable has 4 categeories. (say A, B, C, D) and then how can i get all possible interactions.
A*B, A*C,... A*B*C, A*B*D,... etc.)

Thanks.

Re: How to get all possible multiplicative interactions

Cynthia_sas — Tue, 23 Dec 2008 16:14:05 GMT

Hi:
If you are talking about PROC MEANS and CLASS variables, look at the doc for the TYPES and WAYS statements:
http://support.sas.com/documentation/cdl/en/proc/59565/HTML/default/a000146737.htm

cynthia

Re: How to get all possible multiplicative interactions

Patrick — Fri, 26 Dec 2008 00:16:06 GMT

Hi
Below a code example to get what you asked for.
Have also a look at Proc Mixed and the like - may be that's in the end what you're aiming for.
HTH
Patrick

data have;
do CatVar='a','b','c','d','e','b';
output;
end;
run;

proc sql;
create view Vhave as
select Distinct CatVar
from have
order by CatVar;
quit;

proc transpose data=Vhave out=TransHave;
var CatVar;
run;

proc summary data=TransHave;
class col:;
output out=CombHave(where=(_type_ ne 0));
run;

data want;
set CombHave;
CombVar=cats(of col:);
run;

proc print data=want;
run;

Re: How to get all possible multiplicative interactions

Doc_Duke — Fri, 26 Dec 2008 19:57:08 GMT

In GLM, you can use the "bar operator" (|) to get all possible interactions. I suspect that syntax would work in MIXED as well. Check the syntax in the MODEL statement.

Doc Muhlbaier
Duke