MASS problem -- glmmPQL and anova

Hello:

I am really stuck on this problem. Why do I get an error message with
anova() when I compare these two equations?

Hope someone can help.

ANDREW
____________________________

fm1 <- glmmPQL(choice ~ day + stereotypy,

+                random = ~ 1 | bear, data = learning, family = binomial)

fm2 <- glmmPQL(choice ~ day + envir + stereotypy,

+                random = ~ 1 | bear, data = learning, family = binomial)

anova(fm1, fm2)

Error in anova.lme(fm1, fm2) : Objects must inherit from classes "gls",
"gnls" "lm","lmList", "lme","nlme","nlsList", or "nls"

anova(fm1)

numDF denDF   F-value p-value
(Intercept)     1  2032   7.95709  0.0048
day             1  2032 213.98391  <.0001
stereotypy      1  2032   0.42810  0.5130

anova(fm2)

numDF denDF   F-value p-value
(Intercept)     1  2031   5.70343  0.0170
day             1  2031 213.21673  <.0001
envir           1  2031  12.50388  0.0004
stereotypy      1  2031   0.27256  0.6017

Andrew R. Criswell, Ph.D.
Graduate School, Bangkok University

mailto:andrew.c at bu.ac.th
mailto:andrew at arcriswell.com