Message-ID: <47EB95D0.3070602@ed.ac.uk>
Date: 2008-03-27T12:40:48Z
From: iwhite@staffmail.ed.ac.uk
Subject: use of pedigree structures
The lmer function includes random terms as
(expression for a model matrix|grouping factor)
and I wonder how general the expression can be. For example, a pedigree
object can be converted to an A matrix (in the language of animal
breeding), but can the A matrix be incorporated into an lmer analysis?
I thought that
(chol(pedigree)|ones)
might be OK, where 'ones' is a constant vector of value 1. With the only
example I have tried, the syntax is accepted but the analysis ends with
a forced exit from R (core dump).
--
I White
University of Edinburgh
Ashworth Laboratories, West Mains Road
Edinburgh EH9 3JT (Tel 0131 650 5490)