Hello,

I have a problem concerning estimation of GLMM. I used methods from 3 different 
packages (see program). I would expect similar results for glmm and glmmML. The 
result differ in the estimated standard errors, however. I compared the results to 
MASS, 4th ed., p. 297. The results from glmmML resemble the given result for 
'Numerical integration', but glmm output differs. For the intercept e.g. I have a 
standard error of 0.4354 from glmm and 0.5338 from glmmML. Any idea about this 
problem??

Thanks in advance
Clemens Tilke



library (MASS)
data (bacteria)

contrasts (bacteria$trt) <- structure (contr.sdif (3), 
dimnames = list (NULL, c ("drug", "enc")))
 
bacteria.pql <- glmmPQL (y ~ trt + I(week > 2), random = ~ 1 | 
ID, family = binomial, data = bacteria)

summary (bacteria.pql)

library (repeated)

y1 <- 1 * (bacteria$y == "y")

bacteria1 <- data.frame (bacteria, y1 = y1)

bacteria.glmm <- glmm (y1 ~ trt + I(week > 2), nest = ID, data 
= bacteria1, family = binomial)

summary (bacteria.glmm)

library (glmmML)

bacteria.glmmML <- glmmML (y1 ~ trt + I(week > 2), cluster = 
bacteria1$ID, data = bacteria1, family = binomial)

summary (bacteria.glmmML)

bacteria.glmmML





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