data-budworm: budworm data

In myaseen208/pbkrtest: Parametric Bootstrap and Kenward Roger Based Methods for Mixed Model Comparison

Description

Effect of Insecticide on survivial of tobacco budworms number of killed budworms exposed to an insecticidepp mortality of the moth tobacco budworm 'Heliothis virescens' for 6 doses of the pyrethroid trans-cypermethrin differentiated with respect to sex

Usage

budworm

Format

This data frame contains 12 rows and 4 columns:

sex:

sex of the budworm

dose:

dose of the insecticide trans-cypermethrin in [mug]

ndead:

budworms killed in a trial

ntotal:

total number of budworms exposed per trial

Source

Collet, D. (1991) Modelling Binary Data, Chapman & Hall, London, Example 3.7

References

Venables, W.N; Ripley, B.D.(1999) Modern Applied Statistics with S-Plus, Heidelberg, Springer, 3rd edition, chapter 7.2

Examples

data(budworm)

## function to caclulate the empirical logits
empirical.logit<- function(nevent,ntotal) {
   y <- log((nevent + 0.5) / (ntotal - nevent + 0.5))
   y
}


# plot the empirical logits against log-dose

log.dose <- log(budworm$dose)
emp.logit <- empirical.logit(budworm$ndead, budworm$ntotal)
plot(log.dose, emp.logit, type='n', xlab='log-dose',ylab='emprirical logit')
title('budworm: emprirical logits of probability to die ')
male <- budworm$sex=='male'
female <- budworm$sex=='female'
lines(log.dose[male], emp.logit[male], type='b', lty=1, col=1)
lines(log.dose[female], emp.logit[female], type='b', lty=2, col=2)
legend(0.5, 2, legend=c('male', 'female'), lty=c(1,2), col=c(1,2))

## Not run: 
* SAS example;
data budworm;
infile 'budworm.txt' firstobs=2;
input sex dose ndead ntotal;
run;

## End(Not run)

myaseen208/pbkrtest documentation built on Feb. 21, 2020, 12:13 a.m.