Dear R-users,
I computed a simple mixed models which was:
mod<-lmer(nb ~ site + (1|patelle),tr)
The output was:
Linear mixed-effects model fit by REML
Formula: nb ~ site + (1 | patelle)
Data: tr
AIC BIC logLik MLdeviance REMLdeviance
1157.437 1168.686 -574.7184 1164.523 1149.437
Random effects:
Groups Name Variance Std.Dev.
patelle (Intercept) 34.995 5.9157
Residual 744.736 27.2899
# of obs: 123, groups: patelle, 33
Fixed effects:
Estimate Std. Error t value
(Intercept) 60.3483 4.3929 13.7378
siteLCN -20.1969 7.8070 -2.5870
siteLCS -18.2154 6.1514 -2.9612
Correlation of Fixed Effects:
(Intr) sitLCN
siteLCN -0.563
siteLCS -0.714 0.402
I don't understand why D.F. and p-values associated to the fixed-effects
coefficients are missing.
Could anyone help me?
When I tried another model (mod2<-lmer(nb ~ site +
(1|patelle),tr,family=poisson)), D.F. and p-values were given...
Thank you in advance.
Very sincerely, Simon
BLANCHET Simon
PhD student
Universit?? Laval - Qu??bec-Oc??an / CIRSA
Pavillon Alexandre-Vachon
Local 8022
Qu??bec (Qu??bec), Canada G1K 7P4
T??l??phone : (418) 656-2131 poste 8022
courriel : simon.blanchet at giroq.ulaval.ca
Dear Simon There was a discussion about degrees of freedom in linear mixed models on the R-list last week. Have a look at stat.ethz.ch/pipermail/r-help/2006-January/085560.html and following. There have been earlier discussions about that topic. Try also: RSiteSearch("degree freedom mixed") Regards, Christoph Buser -------------------------------------------------------------- Christoph Buser <buser at stat.math.ethz.ch> Seminar fuer Statistik, LEO C13 ETH (Federal Inst. Technology) 8092 Zurich SWITZERLAND phone: x-41-44-632-4673 fax: 632-1228 stat.ethz.ch/~buser -------------------------------------------------------------- Simon Blanchet writes: > Dear R-users, > > I computed a simple mixed models which was: > > mod<-lmer(nb ~ site + (1|patelle),tr) > > The output was: > > Linear mixed-effects model fit by REML > Formula: nb ~ site + (1 | patelle) > Data: tr > AIC BIC logLik MLdeviance REMLdeviance > 1157.437 1168.686 -574.7184 1164.523 1149.437 > Random effects: > Groups Name Variance Std.Dev. > patelle (Intercept) 34.995 5.9157 > Residual 744.736 27.2899 > # of obs: 123, groups: patelle, 33 > > Fixed effects: > Estimate Std. Error t value > (Intercept) 60.3483 4.3929 13.7378 > siteLCN -20.1969 7.8070 -2.5870 > siteLCS -18.2154 6.1514 -2.9612 > > Correlation of Fixed Effects: > (Intr) sitLCN > siteLCN -0.563 > siteLCS -0.714 0.402 > > I don't understand why D.F. and p-values associated to the fixed-effects > coefficients are missing. > Could anyone help me? > > When I tried another model (mod2<-lmer(nb ~ site + > (1|patelle),tr,family=poisson)), D.F. and p-values were given... > > Thank you in advance. > > Very sincerely, Simon > > > > BLANCHET Simon > PhD student > Universit?? Laval - Qu??bec-Oc??an / CIRSA > Pavillon Alexandre-Vachon > Local 8022 > Qu??bec (Qu??bec), Canada G1K 7P4 > T??l??phone : (418) 656-2131 poste 8022 > courriel : simon.blanchet at giroq.ulaval.ca > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! R-project.org/posting-guide.html