Dear all,
I ran the following model without any problem previously to the update of
lme4:
fm2<-lmer(data=NGud,family=poisson,
seed~hab*seedtray
+(1|site)+(1|site:hab))
I have 25 sites, 2 habitats ("hab") per site, 8 seedtrays per habitat
(4 as
control, and 4 as treatment), and I'm interested in comparing the number of
seed in seedtrays as a function of the treatment and its interaction with
habitat.
My problem is that I have just updated lme4 with the version posted in the
last days. Running the same model implies that R crashes rather than
printing an error message. I read the post of Douglas Bates in the "what
news" section but I don't know what is the new appropriate formulation
for
this model.
Any help would be very appreciated.
Many thanks by advance.
PS: I tested
fm2<-lmer(data=NGud,family=poisson,
seed~hab*seedtray
+(1|site)+(1|site/hab))
which also made R crashing.
And,
fm2<-lmer(data=NGud,family=poisson,
seed~hab*seedtray
+(1|site/hab))
and for this, I obtained :
CHOLMOD warning: matrix not positive definite
Error in devLaplace(PQLpars) : Cholmod error `matrix not positive definite'
at file:../Supernodal/t_cholmod_super_numeric.c, line 614
J?r?me Lema?tre
?tudiant au doctorat
Chaire de recherche industrielle CRSNG - Universit? Laval en sylviculture et
faune
& D?partement de biologie,
Facult? des sciences et de g?nie
Pavillon Alexandre-Vachon
Universit? Laval
Qu?bec, QC G1K 7P4
t?l : (418) 656-2131 poste 2917
Local : VCH-2044
Courriel: jerome.lemaitre.1 at ulaval.ca
