>From the GEE article in R News, Vol. 2/3, December 2002: "Allows different covariates in separate models for the mean, scale, and correlation via various link functions."
Geepack offers link functions for the scale, correlation, and mean models. As the output suggests, "Correlation: Structure = ar1 Link = identity" does not refer to the mean link. In fact, if you look at the output from m.ar you would see: "Scale Link: identity Estimated Scale Parameters: [1] 1 Correlation: Structure = ar1 Link = identity" See the R news article for more info on other correlation and scale link functions. The take home message is this: the mean link is exactly what you think it is, the logit. -tgs On Thu, Apr 29, 2010 at 10:28 AM, Sachi Ito <s.ito....@gmail.com> wrote: > Hi, > > I'm running GEE using geepack. > > I set corstr = "ar1" as below: > > > m.ar <- geeglm(L ~ O + A, > + data = firstgrouptxt, id = id, > + family = binomial, corstr = "ar1") > > > > summary(m.ar) > > Call: > geeglm(formula = L ~ O + A, family = binomial, > data = firstgrouptxt, id = id, corstr = "ar1") > > Coefficients: > Estimate Std.err Wald Pr(>|W|) > (Intercept) -2.62516 0.21154 154.001 <2e-16 *** > ontask 0.00498 0.12143 0.002 0.9673 > attachmentB 0.73216 0.35381 4.282 0.0385 * > attachmentC 0.25960 0.33579 0.598 0.4395 > --- > Signif. codes: 0 *** 0.001 ** 0.01 * 0.05 . 0.1 1 > > Estimated Scale Parameters: > Estimate Std.err > (Intercept) 1.277 0.3538 > > Correlation: Structure = ar1 Link = identity > > Estimated Correlation Parameters: > Estimate Std.err > alpha 0.978 0.005725 > Number of clusters: 49 Maximum cluster size: 533 > > > Then, it shows that : > Correlation: Link = identity > > Why is it not Link = logit? > > > Thank you, > Sachi > > [[alternative HTML version deleted]] > > > ______________________________________________ > R-help@r-project.org 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. > > [[alternative HTML version deleted]]
______________________________________________ R-help@r-project.org 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.
