[R-sig-ME] Error when using models with lmer

[Ista Zahn]

Hi all,

Prof. Bates, I think you missed the "i" in "ci". It took me a while to
figure out, but I think the OP is trying to use ci.mer from the
gmodels package.

Olga, the proper course of action is to contact the gmodels maintainer
to alert them to this bug / incompatibility, as even the ci examples
do not run:

## Example from ci() documentation

fm2 <- lmer(Reaction ~ Days + (1|Subject) + (0+Days|Subject), sleepstudy)
ci(fm2)
Error in as.vector(data) :
  no method for coercing this S4 class to a vector

Best,
Ista

On Wed, Feb 8, 2012 at 11:51 AM, Douglas Bates <bates at stat.wisc.edu> wrote:
> On Tue, Feb 7, 2012 at 2:03 PM, Olga Vitek <ovitek at stat.purdue.edu> wrote:
>> Hello,
>>
>> I am executing the following code
>>
>>> library("lme4")
>>> library(faraway)
>>> data(penicillin)
>>> fit4 <- lmer(yield ~ treat + (1|blend), penicillin)
>>
>> and the lines below generate error messages
>>
>>> library(gmodels)
>>> ci(fit4)
>
> Yes.  Why would you want to try to create a vector from an S4 fitted
> model object?
>
> It almost never makes sense to use
>
> c(foo)
>
> Most of the time when people use that idiom what they really mean is
>
> foo
>
> (I say "almost never" because in the old days many of us would use
> c(myMatrix) to create a vector from a matrix.  The preferred form is
> now as.vector(myMatrix).)
>
>> Error in as.vector(data) :
>>  no method for coercing this S4 class to a vector
>>
>>> contrast.function <- c(0, -1, 0, 0)
>>> test.result <- estimable(fit4, contrast.function)
>> Error in as.vector(data) :
>
> I assume that the "estimable" function is in the gmodels package, so
> you should contact the author of that package about this.
>
>>  no method for coercing this S4 class to a vector
>>
>>
>> This worked with with lme4_0.999375-40 and R version 2.13.1, but not with lme4_0.999375-42 and R version 2.14.1.
>>
>> Would you have suggestions on how to make this work?
>> Thank you in advance
>> Olga Vitek
>>
>>> sessionInfo()
>> R version 2.14.1 (2011-12-22)
>> Platform: i386-apple-darwin9.8.0/i386 (32-bit)
>>
>> locale:
>> [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
>>
>> attached base packages:
>> [1] stats     graphics  grDevices utils     datasets  methods   base
>>
>> other attached packages:
>> [1] gmodels_2.15.1   faraway_1.0.5    lme4_0.999375-42 Matrix_1.0-3     lattice_0.20-0
>>
>> loaded via a namespace (and not attached):
>> [1] gdata_2.8.2   grid_2.14.1   gtools_2.6.2  MASS_7.3-16   nlme_3.1-102  stats4_2.14.1 tools_2.14.1
>> _______________________________________________
>> R-sig-mixed-models at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models
>
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