zero_one: Zero-one transformation for categorical variable

In LSTbook: Data and Software for "Lessons in Statistical Thinking"

Zero-one transformation for categorical variable

Description

A convenience function for handling categorical response variables. Ordinarily, ggplot2 maps categorical levels to numerical values 1, 2, .... Such numerical mapping is inappropriate for logistic modeling, where we want the levels to be on a probability scale.

Usage

zero_one(x, one)

label_zero_one(P)

Arguments

x	a categorical variable
one	character string specifying the level that gets mapped to 1.
P	A ggplot2 object made by model_plot() or point_plot()

Value

A numerical vector of 0s and 1s.

Examples

Birdkeepers |>
  point_plot(zero_one(LC, one="LungCancer") ~ AG + BK, annot = "model")

Birdkeepers |>
  mutate(Condition = zero_one(LC, one = "LungCancer")) |>
  point_plot(Condition ~ AG + BK, annot = "model") |>
  label_zero_one() |>
  add_plot_labels(x="age", color = "Birdkeeper?")

LSTbook documentation built on April 3, 2025, 6:02 p.m.