Plot Sequential ANOVA Results — plot

Creates a visualization of the sequential probability ratio test (SPRT) for ANOVA results, showing the log-likelihood ratio trajectory across sample sizes and decision boundaries.

Usage

plot_anova(
  anova_results,
  labels = TRUE,
  position_labels_x = 0.15,
  position_labels_y = 0.1,
  position_lr_x = NULL,
  position_lr_y = NULL,
  font_size = 15,
  line_size = 1,
  highlight_color = "#CD2626"
)

Arguments

anova_results: A seq_anova_results object from seq_anova(). Important: The seq_anova() function must be called with plot = TRUE to generate the necessary data for plotting.
labels: Logical. If TRUE (default), display decision labels ("Accept H0" / "Accept H1") and the likelihood ratio at the decision point.
position_labels_x: Numeric value between 0 and 1 controlling the horizontal position of decision labels as a proportion of maximum sample size. Default is 0.15 (left side); 0.5 centers the labels.
position_labels_y: Numeric value controlling the vertical spacing between decision boundaries and their labels. The value is multiplied by max(|log-likelihood ratio|) to determine spacing. Larger values move labels further from boundaries. Default is 0.075.
position_lr_x: Optional numeric value for the x-coordinate (sample size) of the likelihood ratio label. If NULL (default), positioned at the decision point or final sample size.
position_lr_y: Optional numeric value for the y-coordinate (log-likelihood ratio) of the likelihood ratio label. If NULL (default), positioned at y = 0 for early decisions, or slightly offset for continuing sampling scenarios.
font_size: Numeric. Base font size for plot text. Default is 20.
line_size: Numeric. Line width for the trajectory and boundaries. Default is 1.5.
highlight_color: Character string. Color for highlighting the decision point or final sample. Default is "#CD2626" (red).

Value

A ggplot2::ggplot() object showing:

Log-likelihood ratio trajectory across sample sizes
Dashed horizontal lines indicating decision boundaries
Highlighted point showing where decision was reached (or final sample)
Optional labels for decision regions and likelihood ratio value

Examples

# simulate data for the example ------------------------------------------------
set.seed(3)
data <- sprtt::draw_sample_normal(3, f = 0.25, max_n = 50)

# calculate the SPRT -----------------------------------------------------------
anova_results <- sprtt::seq_anova(y~x, f = 0.25, data = data, plot = TRUE)

# plot the results -------------------------------------------------------------
# default settings
sprtt::plot_anova(anova_results)

# variant 1
sprtt::plot_anova(anova_results,
                 labels = TRUE,
                 position_labels_x = 0.05,
                 position_lr_x = 150,
                 position_lr_y = 0,
                 highlight_color = "green"
                 )

# variant 2
sprtt::plot_anova(anova_results,
                  labels = TRUE,
                  position_labels_x = 0.15,
                  position_labels_y = 0.2,
                  position_lr_x = 60,
                  position_lr_y = 1,
                  font_size = 25,
                  line_size = 2,
                  highlight_color = "darkred"
)

# no labels
sprtt::plot_anova(anova_results,
                 labels = FALSE
                 )

# custom additions
sprtt::plot_anova(anova_results) +
  ggplot2::geom_vline(xintercept = 66, linewidth = 1, linetype = "dashed")


# further information ----------------------------------------------------------
# run this code:
vignette("one_way_anova", package = "sprtt")
#> Warning: vignette ‘one_way_anova’ not found