an error in gee()

Dear Cahn,

I tend to use the geepack package instead of the gee package. Just
change the name of the package and it works like a charm.

library(geepack)
data(Rail,package="nlme")
geese(travel~1, id=Rail, data=Rail, corstr="exchangeable") 

HTH,

Thierry


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----
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek
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tel. + 32 54/436 185
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-----Oorspronkelijk bericht-----
Van: r-sig-mixed-models-bounces at r-project.org
[mailto:r-sig-mixed-models-bounces at r-project.org] Namens Chaehyung Ahn
Verzonden: donderdag 14 januari 2010 4:14
Aan: r-sig-mixed-models at r-project.org
Onderwerp: [R-sig-ME] an error in gee()

Hi everyone,

I've been trying to fit a simple dataset Rail in nlme package with
gee().

This is what I tried. Rail has 3 repetitions for each id.
----------------------------------------
library(gee)
data(Rail,package="nlme")
gee(travel~1, id=Rail, data=Rail, corstr="exchangeable")
 ----------------------------------------

However, I got the following error;
 ----------------------------------------
Working Correlation[1:4,1:4]
Error in print(x$working.correlation[1:4, 1:4], digits = digits) :
  subscript out of bounds
 ----------------------------------------

I make the Rail have 4 repetitions per each id, then it works.
-----------------------------------------------
Rail1<-rbind(Rail,c(1,53),c(2,30),c(3,87),c(4,95),c(5,48),c(6,84))
aa<-order(Rail1$Rail)
Rail1<-Rail1[aa,]
gee(travel~1, id=Rail, data=Rail1, corstr="exchangeable")
---------------------------------------------------

So, it works with 4 repetitions but with 3 repetitions. Did I do
something wrong or is it a known bug?

Many thanks in advance.

cahn


--
Chaehyung Ahn
4033 Remington Oaks Circle
Cary, NC 27519
http://cahn88.blogspot.com/


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