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.
Usage
linlog(dose, e0, delta, off = 1)
Arguments
dose
Dose variable
e0
Placebo effect
delta
Slope parameter
off
Offset value to avoid problems with dose=0 (treated as a
fixed value in the code)
Value
Response value
Details
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.
References
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