formula in fixed-effects part of GLMM
On Mon, 2005-05-02, 17:24, Douglas Bates wrote:
weihong wrote:
Can GLMM take formula derived from another object?
foo <- glm (OVEN ~ h + h2, poisson, dataset)
# ok
bar <- GLMM (OVEN ~ h + h2, poisson, dataset, random = list (yr = ~1))
#error
bar <- GLMM (foo$formula, poisson, dataset, random = list (yr = ~1))
#Error in foo$("formula" + yr + 1) : invalid subscript type
That won't work without some tweaking of the GLMM function. In the 0.95-1 and later versions of the lme4 package the capabilities of GLMM have been folded in to the lmer function and you would need to fit that model as lmer(OVEN ~ h + h2 + (1|yr), dataset, poisson) anyway.
I don't have access to the "White Book" right now (or R, for that matter), but doesn't it say that something like the following works? fit.lm <- lm(y ~ x) fit.glm <- update(fit.lm, class = "glm") But this isn't implemented in R, right? If one can make a wish, it would be really nice being able to (using weihong's example): bar <- update(foo, . ~ . + (1|yr), class = "lmer") //Henric