plot_thresholds: Add a threshold line to a ROC plot

In ROCnGO: Fast Analysis of ROC Curves

Add a threshold line to a ROC plot

Description

Include a threshold line on an specified axis.

Usage

add_fpr_threshold_line(threshold)

add_tpr_threshold_line(threshold)

add_threshold_line(threshold, ratio = NULL)

Arguments

threshold	A number between 0 and 1, both inclusive, which represents the region bound where to calculate partial area under curve. If ratio = "tpr", it represents lower bound of the TPR region, being its upper limit equal to 1. If ratio = "fpr", it represents the upper bound of the FPR region, being its lower limit equal to 0.
ratio	Ratio in which to display threshold. If "tpr" threshold will be displayed in TPR, y axis If "fpr" it will be displayed in FPR, x axis.

Value

A ggplot layer instance object.

Examples

# Add two threshold line in TPR = 0.9 and FPR = 0.1
plot_roc_curve(iris, response = Species, predictor = Sepal.Width) +
 add_threshold_line(threshold = 0.9, ratio = "tpr") +
 add_threshold_line(threshold = 0.1, ratio = "fpr")
# Add threshold line in TPR = 0.9
plot_roc_curve(iris, response = Species, predictor = Sepal.Width) +
 add_tpr_threshold_line(threshold = 0.9)
# Add threshold line in FPR = 0.1
plot_roc_curve(iris, response = Species, predictor = Sepal.Width) +
 add_fpr_threshold_line(threshold = 0.1)

ROCnGO documentation built on Aug. 8, 2025, 6:07 p.m.