R help - Apr 2005 - formula in fixed-effects part of GLMM

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

I am using R2.1.0, lme4 0.8-2, windows xp.  Below is a dataset if you need (yr
is a factor).
> dataset
   OVEN  h  h2 yr
1     2 30 900  0
2     3 30 900  1
3     4 30 900  2
4     3 30 900  3
5     3 30 900  4
6     1 25 625  0
7     2 25 625  1
8     1 25 625  2
9     1 25 625  3
10    2 25 625  4

Thanks ahead!

Weihong Li
Undergraduate student
University of Alberta

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.

> From: Douglas Bates
> 
> Henric Nilsson wrote:
> > 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
> 
> It's not very convenient from the point of view of dispatch.  The
> dispatch rules are such that the update method for the lm or glm class
> would need to be aware of the lmer class to be able to do 
> this.  The lm
> and glm classes predate lmer by a long time.
In that case, wouldn't lmer also need to be in "stats" (or
somewhere "stats"
can import from)?

Best,
Andy