topic Product terms as all combinations of two variables in regression in SAS Programming

Product terms as all combinations of two variables in regression

TJ87 — Thu, 20 Oct 2016 23:33:14 GMT

Say I have 5 variables (A-E) and I would like to test all the 2-way product term interactions between them (A*B, B*C, etc). Could someone please suggest a simple program to (a) create these product term variables, and (b) test each one in Proc Logistic, including the two original variables (A,B) and the product term (A*B)? Thank you.

Re: Product terms as all combinations of two variables in regression

Reeza — Thu, 20 Oct 2016 23:52:57 GMT

Specify full model as

model y = a | b | c @2 ;

See the documentation here:

https://communities.sas.com/t5/SAS-Communities-Library/SAS-9-4-Macro-Language-Reference-Has-a-New-Appendix/ta-p/291716

Re: Product terms as all combinations of two variables in regression

TJ87 — Fri, 21 Oct 2016 01:31:58 GMT

Hi Reeza,

My understanding is that this will give all combinations in one model:

y=a b c a*b a*c b*c

Is that correct? I'd like to model each product term separately.

y(1)=a b a*b

y(2)=a c a*c

y(3)=b c b*c

Thanks.