drc (version 1.2-0)

glymet: Glyphosate and metsulfuron-methyl tested on algae.

Description

The dataset has 7 mixtures, 8 dilutions, two replicates and 5 common control controls. Four observations are missing, giving a total of 113 observations.

Usage

data(glymet)

source

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

Details

The dataset is analysed in S{\o}rensen et al (2006). The hypothesis of concentration addition can be entertained for this dataset.

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=glymet, collapse=~factor(pct1), 
fct=l3(), model="CA", boxcox=TRUE)
anova(model1ca)  # comparison to model with freely varying e parameter
summary(model1ca)


## Fitting the Hewlett model
model1h <- mixture(rgr1~dose1, pct1, data=glymet, collapse=~factor(pct1), 
fct=l3(), model="Hewlett", boxcox=TRUE)
anova(model1h)  # comparison to a model with freely varying e parameter
anova(model1ca, model1h)  # concentration addition is accepted
summary(model1h)


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


rm(model1ca, model1h, model1v)