R/plot_auxboxplot.R

In goodekat/ggResidpanel: Panels and Interactive Versions of Diagnostic Plots using 'ggplot2'

# Boxplot of Residuals.

# Creates a boxplot from input residuals and predicted values
plot_auxboxplot <- function(
    resid, 
    theme, 
    axis.text.size, 
    title.text.size, 
    title.opt
  ){

  ## Creation of Values to Plot -----------------------------------------------------
  
  # Create a data frame with the residuals
  model_values <- data.frame(Residual = resid)
  
  # Add an observation variable
  model_values$Observation <- 1:nrow(model_values)
  
  ## Creation of Plot ---------------------------------------------------------------
  
  # Create the boxplot of residuals
  plot <-
    ggplot(
      data = model_values, 
      mapping = aes(
        x = " ",
        y = .data$Residual
      )
    ) +
    geom_boxplot(width = .5) +
    geom_point(alpha = 0) +
    labs(
      x = " ", 
      y = "Residuals"
    )
  
  # Add theme to plot
  if (theme == "bw") {
    plot <- plot + theme_bw()
  } else if (theme == "classic") {
    plot <- plot + theme_classic()
  } else if (theme == "gray" | theme == "grey") {
    plot <- plot + theme_grey()
  }
  
  # Set text size of title and axis labels,
  # determine whether to include a title,
  # and return plot
  if (title.opt == TRUE) {
    plot +
      labs(title = "Boxplot") +
      theme(
        plot.title = element_text(size = title.text.size, face = "bold"),
        axis.title = element_text(size = axis.text.size)
      )
  } else if (title.opt == FALSE) {
    plot +
      theme(axis.title = element_text(size = axis.text.size))
  }
  
}