gf_resid: Add Residual Lines to a Plot

In coursekata: Packages and Functions for 'CourseKata' Courses

Add Residual Lines to a Plot

Description

This function adds vertical lines representing residuals from a linear model to a ggformula plot. The residuals are drawn from the observed data points to the predicted values from the model.

Usage

gf_resid(plot, model, linewidth = 0.2, ...)

Arguments

plot	A ggformula plot object, typically created with gf_point().
model	A fitted linear model object created using lm().
linewidth	A numeric value specifying the width of the residual lines. Default is 0.2.
...	Additional aesthetics passed to geom_segment(), such as color, alpha, linetype.

Value

A ggplot object with residual lines added.

Examples

Height_model <- lm(Thumb ~ Height, data = Fingers)
gf_point(Thumb ~ Height, data = Fingers) %>%
  gf_model(Height_model) %>%
  gf_resid(Height_model, color = "red", alpha = 0.5)

coursekata documentation built on Aug. 12, 2025, 1:06 a.m.