utility_formula {spdesign}

Create formulas from the utility functions

Description

Create formulas from the utility functions such that we can create correct model matrices.

Usage

utility_formula(x)

Arguments

x

An object of class utility

Details

Note that this function should be used on a cleaned utility expression and **not** an updated utility expression. This is because we are converting dummy coded attributes to factors prior to calling model.matrix. This ensures that dummy coded attributes are correctly returned with the model matrix.

Value

A list of formula expressions for the utility functions