[R-sig-ME] How to extract num. of observations and groups used in a mixed model using gee package

[david oseguera montiel]

David,
Thank you very much. Number of observations solved, but I am still 
missing how to find out the number of groups used. In the warpbreaks 
data set these are 2. Any ideas. Thank you.

On 23/04/2012 13:28, David Winsemius wrote:
>
> On Apr 23, 2012, at 12:44 PM, david oseguera montiel wrote:
>
>> Does anyone know how can extract the number of observations and 
>> groups used
>> in a mixed model with gee package?
>> The summary function in gee package does not provide this information.
>> e.g.
>> data(warpbreaks)
>> summary(gee(breaks ~ tension, id=wool, data=warpbreaks,
>> corstr="exchangeable"))
>
> Does this address all of those puzzles?
>
> summgee <- summary(gee(breaks ~ tension, id=wool, data=warpbreaks,  
> corstr="exchangeable"))
> Beginning Cgee S-function, @(#) geeformula.q 4.13 98/01/27
> running glm to get initial regression estimate
> (Intercept)    tensionM    tensionH
>    36.38889   -10.00000   -14.72222
> > names(summgee)
>  [1] "call"                "version"             "nobs"                
> "residual.summary"
>  [5] "model"               "title"               "coefficients"        
> "working.correlation"
>  [9] "scale"               "error"               "iterations"
> > summgee$nobs
> [1] 54
>
> > summgee$call
> gee(formula = breaks ~ tension, id = wool, data = warpbreaks,
>     corstr = "exchangeable")
> > summgee$coefficients
>              Estimate Naive S.E.   Naive z Robust S.E.  Robust z
> (Intercept)  36.38889   3.069434 11.855246    5.774705  6.301428
> tensionM    -10.00000   3.910008 -2.557539    7.463905 -1.339781
> tensionH    -14.72222   3.910008 -3.765266    3.731952 -3.944912
> > rownames(summgee$coefficients)
> [1] "(Intercept)" "tensionM"    "tensionH"
>
>>
>> I much appreciate any help,
>>
>> David Oseguera Montiel
>> Phd student Wageningen University
>>
>> pd. I asked this a few days ago in R-help list and I did not get any 
>> answer yet.
>>
>> _______________________________________________
>> R-sig-mixed-models at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models
>
> David Winsemius, MD
> West Hartford, CT
>