dose.p {MASS} | R Documentation |
Calibrate binomial assays, generalizing the calculation of LD50.
dose.p(obj, cf = 1:2, p = 0.5)
obj |
A fitted model object of class inheriting from "glm" .
|
cf |
The terms in the coefficient vector giving the intercept and coefficient of (log-)dose |
p |
Probabilities at which to predict the dose needed. |
An object of class "glm.dose"
giving the prediction (attribute
"p"
and standard error (attribute "SE"
) at each response
probability.
Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Springer.
ldose <- rep(0:5, 2) numdead <- c(1, 4, 9, 13, 18, 20, 0, 2, 6, 10, 12, 16) sex <- factor(rep(c("M", "F"), c(6, 6))) SF <- cbind(numdead, numalive = 20 - numdead) budworm.lg0 <- glm(SF ~ sex + ldose - 1, family = binomial) dose.p(budworm.lg0, cf = c(1,3), p = 1:3/4) dose.p(update(budworm.lg0, family = binomial(link=probit)), cf = c(1,3), p = 1:3/4)