Doug,
It's mitools, not mltools. I wrote it.
I think the problem is just that coef() is not the right function for
getting the fixed effects. Beth wants
betas <- MIextract(model0, fun=fixef)
-thomas
On Sat, 3 Mar 2007, Douglas Bates wrote:
> On 3/2/07, Beth Gifford <[EMAIL PROTECTED]> wrote:
>> Hey there
>> I am estimating a multilevel model using lmer. I have 5 imputed datasets so
>> I am using mitools to pool the estimates from the 5
>> datasets. Everything seems to work until I try to use
>> MIcombine to produced pooled estimates. Does anyone have any suggestions?
>> The betas and the standard errors were extracted with no problem so
>> everything seems to work smoothly up until that point.
>
> I'm not familiar with the mltools package and I didn't see it listed
> in the CRAN packages. Can you provide a reference or a link to the
> package?
>
>>> Program
>>> #Read data
>>> data.dir<-system.file("dta",package="mitools")
>>> files.imp<-imputationList(lapply(list.files(data.dir,
>>> pattern="imp.\\.dta", full=TRUE), read.dta))
>>>
>>> #estimate model over each imputed dataset
>>> model0<-with(files.imp,lmer( erq2tnc ~1+trt2+nash+wash+male+coh2+coh3+(1 |
>>> sitebeth)))
>>> #extract betas and standard errors
>>> betas<-MIextract(model0,fun=coef)
>>> vars<-MIextract(model0,fun=vcov)
>>> #Combine the results
>>> summary(MIcombine(betas,vars))
>
>>> Error in cbar + results[[i]] : non-numeric argument to binary operator
>>> Error in summary(MIcombine(betas, vars)) :
>>> error in evaluating the argument 'object' in selecting a method for
>>> function 'summary'
>
> First use traceback() to discover where the (first) error occurred.
> My guess is that Mlcombine expects a particular type of object for the
> vars argument and it is not getting that type (and not checking for
> the correct type).
>
>>
>>
>>
>> Thanks
>> Beth
>>
>> [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> [email protected] mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
> ______________________________________________
> [email protected] mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
Thomas Lumley Assoc. Professor, Biostatistics
[EMAIL PROTECTED] University of Washington, Seattle
______________________________________________
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