[R] help with nls and Hill equation

Christian Ritz ritz at life.ku.dk
Tue Oct 16 16:01:22 CEST 2007


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



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