[R-sig-ME] Can we fit this model in nlme or lme4? Monday, March 28, 2011 8:10 PM

[Ben Bolker]

Haoda Fu <fuhds at ...> writes:

> 
> Hi,
> 
> I was wondering if the following model can be fitted by nlme/lme4. 
> The difficult part is that the error term
> is combined with other parameters.
> The model that we need to fit is as below and the R codes 
> to generate data is provided as well. Many thanks!!!
> 
> # Y_{ijk} = (E_0 + Emax*dose_i/(ED_50+dose_i) + 
>  S_{ij} + e_{ijk})*(1-exp(k*X_{ijk}))/(1-exp(k*d));
> ## Parameters to be estimated E0, Emax, ED50, sigma_S, sigma_e, kn
> 

  Thank you for the clear example.

  But no, I don't see any way to do this in nlme/lme4
(or in any other R mixed modeling package).
  WinBUGS, AD Model Builder ...

  Happy as always to be corrected by someone more knowledgeable.

  Ben Bolker