search for: nlmr1

...gradient attribute of evaluated model must be a numeric matrix and I wonder what this may indicate. The nonlinear model I try to fit is as follows: > grModel function(x,w,Tmin,Tmax,Topt,kopt,m)((x-Tmin)*(x-Tmax))/((x-Tmin)*(x-Tmax)-(x-Topt)^2)*kopt*w^m and my call of nlmer is as follows: nlmr1<-nlmer(feed~grModel(temp,MW,Tmin,Tmax,Topt,kopt,m)~kopt| flat,data=egi,start=c(Tmin=0.2,Tmax=21.1,Topt=14.6,kopt=2.5,m=.51)) 'flat' is a factor with 11 levels. My start values are from nls that fits the model with no errors. The call I have used is as follows: nls1<-nls(feed~grMode...