Implements drc nonlinear functions into the nlme framework for nonlinear GLS dose-response modeling.
glsdrm(form, curveid = NULL, data, fct, correlation = NULL, weights = NULL, control = NULL, start = NULL)
| form | Formula describing the dose-response relationship |
|---|---|
| curveid | Formula with parameter names on the left hand side (divided by +) and a column name in data, denoting a factor, to estimate separate parameters per factor-level. If NULL only fixed effects for a single curve will be estimated. |
| data | a data.frame object |
| fct | a function of the drc package |
| correlation | additional corClasses object |
| weights | additional varClasses object |
| control | list with nlme control arguments |
| start | optional list with initial values for the fixed components. If NULL the initial values will be found automatically |
An object of class glsdrc
An application of glsdrm is shown on the help pages of data broccoli. EDx and selectivity indices can be calculated with functions ED and EDcomp. Model-averaged ED can be computed by function mmaED.