getFix: Get Information on Fixed Effects From a Model Object

In carEx: Supplemental and Experimental Functions

Description

getFix extracts coefficients, their covariance matrix, and degrees of freedom from a model object. Its main purpose is to extract information needed by the wald function. To extend the wald function to a new class of model objects, it is merely necessary to write a method for getFix.

Usage

getFix(fit, ...)

## S3 method for class 'multinom'
getFix(fit, ...)

## S3 method for class 'lm'
getFix(fit, ...)

## S3 method for class 'glm'
getFix(fit, ...)

## S3 method for class 'lme'
getFix(fit, ...)

## S3 method for class 'gls'
getFix(fit, ...)

## S3 method for class 'merMod'
getFix(fit, ...)

## S3 method for class 'zeroinfl'
getFix(fit, ...)

## S3 method for class 'mipo'
getFix(fit, ...)

## S3 method for class 'MCMCglmm'
getFix(fit, ...)

## S3 method for class 'stanfit'
getFix(fit, pars, include = TRUE, ...)

## Default S3 method:
getFix(fit, ...)

Arguments

fit	A fitted model object
pars	For the stanfit method; see extract.
include	For the stanfit method; see extract.
...	Other arguments [unused]

Details

Extending the wald function to a new class of objects only requires a getFix method for the new class.

Value

Returns a list with the following components:

• fixed fixed effect parameter estimates

• vcov covariance matrix of the parameters

• df denominator degrees of freedom for each effect

Methods (by class)

• multinom: method for multinom objects in package nnet

• lm: method for lm objects

• glm: method for glm objects

• lme: method for lme objects in the nlme package

• gls: method for gls objects in the nlme package

• merMod: method for merMod objects in the lme4 package

• zeroinfl: method for zeroinfl objects in the pscl package

• mipo: method for mipo objects in the mice package

• MCMCglmm: method for MCMCglmm objects in the MCMCglmm package

• stanfit: method for stanfit objects in the rstan package

• default: prints an error message if getFix is used for a class for which a method has not been written

Author(s)

Georges Monette

See Also

wald

Examples

mod.prestige <- lm(prestige ~ education + income, data=Prestige)
getFix(mod.prestige)

## Not run: 
# Example of a getFix method for a glm object:

print(carEx:::getFix.glm)

# Example of a getFix method for a mipo object in the mice package:

print(carEx:::getFix.mipo)

## End(Not run)

carEx documentation built on June 28, 2019, 3:01 p.m.