Thanks. I am just not used to having such a huge difference when changing the initial condition by 1 point. it usually tends to be an issue when you are way off (especially since the hill converged at 1.69). Does it have something to do with the algorithm or is the hill just very finicky?
Lanre On 10/16/07, Christian Ritz <[EMAIL PROTECTED]> wrote: > Hi! > > I would suggest trying out a few different starting values as a first > unsystematic approach. > > For example changing hill=1 to hill=2 results in convergence: > > foo.nls<-nls(var~Emax*(Dose^hill)/((EC50^hill)+(Dose^hill)), > start=list(Emax=-4,EC50=269,hill=2),trace=T,data=foo) > > > > Christian > > ______________________________________________ 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.
