drc (version 1.3-0)

deguelin: Deguelin applied to chrysanthemum aphis

Description

Quantal assay data from an experiment where the insectide deguelin was applied to Macrosiphoniella sanborni.

Usage

data(deguelin)

source

Morgan, B. J. T. (1992) Analysis of Quantal Response Data, London: Chapman & Hall/CRC (Table 3.9, p. 117).

Details

The log-logistic model provides an inadequate fit. The dataset is used in Nottingham and Birch (2000) to illustrate a semiparametric approach to dose-response modelling.

References

Notttingham, Q. J. and Birch, J. B. (2000) A semiparametric approach to analysing dose-response data, Statist. Med., 19, 389--404.

Examples

## Log-logistic fit
deguelin.m1<-drm(r/n~dose, weights=n, data=deguelin, fct=LL.2(), type="binomial")
anova(deguelin.m1)
summary(deguelin.m1)

## Loess fit
deguelin.m2<-loess(r/n~dose, data=deguelin, degree=1)

## Plot of data with fits superimposed
plot(deguelin.m1, ylim=c(0.2,1))
lines(1:60, predict(deguelin.m2, newdata=data.frame(dose=1:60)), col = 2, lty = 2)

lines(1:60, 0.95*predict(deguelin.m2, 
newdata=data.frame(dose=1:60))+0.05*predict(deguelin.m1, newdata=data.frame(dose=1:60), se = FALSE),
col = 3, lty=3)