Confidence Intervals for Model Parameters

confint

Description

Returns the confidence intervals for model parameters.

Usage

confint(object, parm, level = 0.95, ...)
## Default S3 method:
confint(object, parm, level = 0.95, ...)
## S3 method for class 'glm':
confint(object, parm, level = 0.95, ...) 
## S3 method for class 'lm':
confint(object, parm, level = 0.95, ...)

Arguments

object	a fitted model.
parm	a character string vector. Indicates for which coefficients of the fitted model, object, to compute confidence intervals. If this argument is missing, confint uses all parameters.
level	indicates the confidence level for confidence intervals. Must be between 0 and 1, and is usually close to 1.
...	additional arguments to be passed to corresponding functions in package MASS.

Details

In generic methods of class "glm" and "nls", use the corresponding methods in the package "MASS" to calculate the confidence interval. The confidence interval is labeled as (1 - level)/2 and (1 + level)/2.

Value

returns the confidence interval for the values of parm.

See Also

MASS:::confint.glm, MASS:::confint.nls

Examples

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.lg <- glm(SF ~ sex*ldose, family = binomial)
confint(budworm.lg)
confint.default(budworm.lg)# based on asymptotic normality
lm.fit <- lm(y ~ ., data=Sdatasets::freeny)
confint(lm.fit)

Package stats version 6.1.1-7
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