[R] GLMM

[Douglas Bates]

Bossarte, Robert wrote:
> I am trying to use the LME package to run a multilevel logistic model
> using the following code:
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> Model1 = GLMM(WEAP ~ TSRAT2 , random = ~1 | GROUP , family = binomial,
> na.action = na.omit )
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> Where WEAP is a dichotomous outcome measure, TSRAT2 is a group level
> covariate, and GROUP is the grouping variable.
> 
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> I do not have significant missing data and the dataset is over 15000
> cases.
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> I have tried changing the outcome measure(s) and predictor(s) with the
> same result. Each time R fails and returns the following message:
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> structure(list( : flist must be a non-empty list of factors
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> This appears to be problem with the grouping variable, yet there are no
> missing values and the data were sorted on this variable prior to being
> read into R.

Is the grouping variable a factor?  Check with

str(GROUP)

If it isn't a factor then convert it a factor using

GROUP <- factor(GROUP)

> 
>  
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> Any suggestions would be greatly appreciated.