The model function for the linear in log model is defined as $$ f(d,\theta)=E_0+\delta \log(d + off)$$ where \(off\) is an offset parameter not estimated in the code.
linlog(dose, e0, delta, off = 1)Dose variable
Placebo effect
Slope parameter
Offset value to avoid problems with dose=0 (treated as a fixed value in the code)
Response value
The linear in log-dose model is intended to capture concave
shapes. The parameter off is not estimated in the code
but set to a pre-specified value.
Pinheiro, J. C., Bretz, F. and Branson, M. (2006). Analysis of dose-response studies - modeling approaches, in N. Ting (ed.). Dose Finding in Drug Development, Springer, New York, pp. 146--171
logistic, sigEmax,
linear, exponential, quadratic,
emax, betaMod