MASSExtra: vcovx – R documentation

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vcovx

Extended variance matrix

Description

An extension to the vcov function mainly to cover the additional parameter involved in negative binomial models. (Currently the same as vcov apart from negative binomial models.)

Usage

vcovx(object, ...)

## Default S3 method:
vcovx(object, ...)

## S3 method for class 'negbin'
vcovx(object, ...)

Arguments

`object`	A fitted mdel objeds
`...`	currently ignored

Value

An extended variance matrix including parameters addition to the regression coefficients

Examples

fm <- glm.nb(Days ~ Sex/(Age + Eth*Lrn), quine)
Sigma <- vcovx(fm)

MASSExtra

Some 'MASS' Enhancements

v1.1.2

GPL-2 | GPL-3

Authors

Bill Venables

Initial release