coefprobit {LW1949}

Calculate the Coefficients of a Probit Regression Fit

Description

Calculate the coefficients from a fitted probit regression model with confidence intervals.

Usage

coefprobit(pfit, alpha = 0.05)

Arguments

pfit

An object of class glm representing a probit regression fit to dose-effect data, typically the result of a call to fitprobit. Dose should be the only independent variable in the model.

alpha

A numeric scalar, the significance level used to generate 100*(1 - alpha)% confidence limits, default 0.05.

Value

A numeric vector of length six, the intercept and slope of the dose-response curve, each with 100*(1 - alpha)% confidence limits.

Examples

toxdat <- data.frame(
 dose=c(0.05, 0.0625, 0.125, 0.25, 0.5, 1),
 ntot=rep(8, 6),
  nfx = c(0, 1, 4, 4, 6, 8))
myfit <- fitprobit(toxdat)
coefprobit(myfit)