topic Re: Class Statement in proc genmod in SAS Programming

Class Statement in proc genmod

fayez61 — Fri, 28 Oct 2016 14:43:34 GMT

Hello,

I want to know if there is a way that I can elimnate refrence option in class statement using genmod procedure?

Because when I run my model, it gives me the last category of each variable in the class as a reference to that variable.

Re: Class Statement in proc genmod

Rick_SAS — Fri, 28 Oct 2016 15:05:00 GMT

A classification variable compares the effect of each level to SOMETHING. Often the comparison is to a reference level, but it could also be to last level, the first level, or the average effect over all levels.

The documentation for "Parameterization of Model Effects" discusses the various ways to choose a parameterization for a CLASS variable. For interpretation and applications of different parameterizations, see Pasta (2005).

For PROC GENMOD, you can use the PARAM= option to choose the parameterization. For example:

CLASS C / param=effect ref='MyRefLevel';

Re: Class Statement in proc genmod

Ksharp — Sat, 29 Oct 2016 04:51:48 GMT

So you need GLM parameterize ? CLASS C / param=glm