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Add a threshold line to a ROC plot

plot_thresholds.Rd

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.

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)