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

[David Winsemius]

On Apr 23, 2012, at 11:25 PM, david oseguera montiel wrote:

> 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.
>
I must be unclear what you mean by "number of groups".
-- 
David.


> 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
>>
>

David Winsemius, MD
West Hartford, CT