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rbmi (version 1.7.1)

formula_has_interaction: Check whether a variable participates in a formula interaction

Description

Check whether a variable participates in a formula interaction

Usage

formula_has_interaction(formula, variable)

Value

A single logical value indicating whether an interaction term involves variable, including through a transformation such as factor(variable).

Arguments

formula

A model formula.

variable

Character, the name of the variable to check.

Details

Uses expanded model terms, so interactions removed with - do not count. Arithmetic inside I() is not treated as a formula interaction.