doBy (version 4.6-3)

data-budworm: budworm data

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 [\(\mu\)g]

ndead:

budworms killed in a trial

ntotal:

total number of budworms exposed per trial

References

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

Examples

# NOT RUN {
data(budworm)

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


# 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;
# }
# NOT RUN {

# }