[R] parameterization of factor in R

Oana Mocila oanaom at hotmail.com
Tue Dec 27 19:58:23 CET 2005


Hi all,

I encountered this problem with parameterization in R:

I have two factors in a regression. how about if I want to
set constraint so that for each factor, the sum of their
coefficients equals to zero(instead of choosing a reference
category)? for example, I have factor(variable) A(with three
categories) and factor(variable) B(with 4 categories), and I want
to parameterize so that the sum of the three coefficients of
A = 0, and sum of the four coefficients of B = 0? I
mean how to do it in R?

Oana

_________________________________________________________________
Don’t just search. Find. Check out the new MSN Search!




More information about the R-help mailing list