drc (version 0.8-2)

mixdrc: Fitting multiple dose-response curves with random effects

Description

'mixdrc' fits non-linear mixed models where random effects are assigned to some or all of the parameters.

Usage

mixdrc(object, random, lambda = 1, data)

Arguments

object

an object of class 'drc'.

random

a character string specifying the random effects. Specification is as in nlme.

lambda

numeric specifying the value of the Box-Cox transformation.

data

a data frame containing the variables in the model (not optional).

Value

• An object of classes 'drc' and 'nlme'.

Details

The function searches through a range of initial values in order to obtain convergence of the estimation procedure.

Examples

## First fitting model without random effects
model1 <- multdrc(SLOPE~DOSE, CURVE, data=PestSci,
collapse=data.frame(HERBICIDE, 1, 1, HERBICIDE))

## Then fitting model with random effects (assigned to d)
model2<-mixdrc(model1, random="d~1|CURVE", data=PestSci)
compParm(model2, "e", "-")

rm(model1, model2)