is.formula {bazar}

Test if an object is a formula

Description

The function is.formula tests if the object x is a formula.

Usage

is.formula(x)

Arguments

x

An object.

Value

A logical, TRUE if x is a formula.

Examples

is.formula("this is a formula")
is.formula(f <- formula("y ~ x"))
is.formula(update(f, ~ . -1))