sigmaHat {car}

Return the scale estimate for a regression model

Description

This function provides a consistent method to return the estimated scale from a linear, generalized linear, nonlinear, or other model.

Usage

sigmaHat(object)

Arguments

object

A regression object of type lm, glm or nls

Details

For an lm or nls object, the returned quantity is the square root of the estimate of \sigma^2. For a glm object, the returned quantity is the square root of the estimated dispersion parameter.

Value

A nonnegative number

Author(s)

Sanford Weisberg, [e-mail]

Examples

m1 <- lm(prestige ~ income + education, data=Duncan)
sigmaHat(m1)