termec {drc}R Documentation

Mechlorprop and terbythylazine tested on Lemna minor

Description

Data consist of 5 mixture, 6 dilutions, three replicates, and 12 common controls; in total 102 onservations.

Usage

data(termec)

Format

A data frame with 102 observations on the following 4 variables.

cell
a numeric vector
dose1
a numeric vector
pct1
a numeric vector
rgr1
a numeric vector

Details

The dataset is analysed in S{o}rensen et al (2006). The asymmetric Voelund model is appropriate, whereas the symmetric Hewlett model is not.

Source

The dataset is kindly provided by Nina Cedergreen, Department of Agricultural Sciences, Royal Veterinary and Agricultural University, Denmark.

References

S{o}rensen, H. and Cedergreen, N. and Skovgaard, I. M. and Streibig, J. C. (2006) An isobole-based statistical model and test for synergism/antagonism in binary mixture toxicity experiments, Statistical Ecology and Environmental Statistics, 13. ?–??.

Examples


## Fitting the concentration addition model
model1ca <- mixture(rgr1~dose1, pct1, data=termec, collapse=~1, 
fct=l3(), model="CA", boxcox=TRUE, bcAdd=0.02)
anova(model1ca)  # comparison to model with freely varying e parameter
summary(model1ca)

## Fitting the Hewlett model
model1h <- mixture(rgr1~dose1, pct1, data=termec, collapse=~1, 
fct=l3(), model="Hewlett", boxcox=TRUE, bcAdd=0.02)
anova(model1h)  # comparison to a model with freely varying e parameter
anova(model1ca, model1h)
summary(model1h)

## Fitting the Voelund model
model1v<-mixture(rgr1~dose1, pct1, data=termec, collapse=~1, 
fct=l3(), model="Voelund", boxcox=TRUE, bcAdd=0.02)
anova(model1v)  # comparison to a model with freely varying e parameter
summary(model1v)

rm(model1ca, model1h, model1v)

[Package drc version 1.3-0 Index]