lrtest_removeTerm: Likelihood ratio p-values for full model vs model with one...

In jenniferthompson/JTHelpers: Personal Helper Functions, Some Related to rms Package

Description

Runs model without 'removeTerm' and performs likelihood ratio test for full model vs nested model. 'function(variable)' - eg, 'rcs(age, 3)' - is considered one term, as are all levels of a categorical variable.

Usage

lrtest_removeTerm(orgModel, removeTerm, ...)

## Default S3 method:
lrtest_removeTerm(orgModel, removeTerm)

## S3 method for class 'mira'
lrtest_removeTerm(orgModel, removeTerm, miceObjName)

Arguments

orgModel	Model object containing full model.
removeTerm	Character string of term(s) to be removed.
...	Additional arguments specific to method.
miceObjName	Character string; name of 'mice' object.
orgModel	Model object containing full model.
removeTerm	Character string of term(s) to be removed.
orgModel	Model object containing full model.
removeTerm	Character string of term(s) to be removed.

Value

List with following values from lrtest() or pool.compare(): test degrees of freedom, X^2^ value, and p-value.

Methods (by class)

• default: Default method.

• mira: Method for models fit with the mice package.

See Also

lrtest_removeTerm.default, lrtest_removeTerm.mira.

lrtest.

pool.compare.

Examples

## Fit full model using iris data
fullModel <- lm(Sepal.Length ~ Sepal.Width + Petal.Length + Petal.Width, data = iris)

## What about just the effect of Petal.Length?
lrtest_removeTerm(fullModel, 'Petal.Length')

## What about the effect of both Petal variables?
lrtest_removeTerm(fullModel, 'Petal.Length + Petal.Width')


## Add missingness to iris data
iris_missing <- iris
iris_missing[sample(1:nrow(iris), size = round(nrow(iris_missing) / 10)), 'Sepal.Width'] <- NA

## Create mice object
iris_mice <- mice(iris_missing)

#' ## Fit full model using iris data
fullModel <- with(iris_mice, lm(Sepal.Length ~ Sepal.Width + Petal.Length + Petal.Width))

## What about just the effect of Petal.Length?
lrtest_removeTerm(fullModel, 'Petal.Length', 'iris_mice')

## What about the effect of both Petal variables?
lrtest_removeTerm(fullModel, 'Petal.Length + Petal.Width', 'iris_mice')

jenniferthompson/JTHelpers documentation built on May 19, 2019, 4:04 a.m.