R: Test if a Model's Formula is Empty

is.empty.model {stats}

R Documentation

Test if a Model's Formula is Empty

Description

R's formula notation allows models with no intercept and no predictors. These require special handling internally. is.empty.model() checks whether an object describes an empty model.

Usage

is.empty.model(x)

Arguments

`x`	A `terms` object or an object with a `terms` method.

Value

TRUE if the model is empty

Examples

y <- rnorm(20)
is.empty.model(y ~ 0)
is.empty.model(y ~ -1)
is.empty.model(lm(y ~ 0))