[R-sig-ME] Nested fixed factors in glmer: Error in mer_finalize(ans) : Downdated X'X is not positive definite, 1.

[Hugo.Mildenberger at web.de]

On Thu, 28 Feb 2013 14:27:36 +0100
"PALACIO BLASCO, SARA" <s.palacio at ipe.csic.es> wrote:

> Maybe this is a trivial question but: how can I specify a nested  
> structured of fixed factors in glmer?
> 
> I still haven't found a way to solve the issues explained in my  
> previous e-mail.


Sara,

may be this fits your needs?

> a<-factor(c('a','b','c','d'))
> b<-factor(c('1','2'))
> interaction(a,b)
[1] a.1 b.2 c.1 d.2
Levels: a.1 b.1 c.1 d.1 a.2 b.2 c.2 d.2


Best