On Sat, 16 Dec 2006, [EMAIL PROTECTED] wrote: > I have would like to use logistic regression to analyze the > percentage of correct responses in a 2 alternative forced > choice task. The question is whether one needs to take into > account the fact expected probabilities for the percentage of > correct responses ranges between 0.5 and 1 in this case.
Yes. > Second, how can one implement a link function of the > type f(x) = (1+exp(x)/(1+exp(x)))/2 in R? Looking at make.link() should give you enough to go on. > Third, can it be also done with gee and/or glmm? For gee, you need to change the C-level internals. (I've done this in the far past for S-PLUS but not for R.) It would be easier to use yags (but I think you still need to dive into the internals). What 'glmm' did you have in mind? Looks like e.g. glmmML and glmmPQL will work with the new link. [...] Someone may have been here already: e.g. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1434755 -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ [email protected] 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.
