find_optimal_threshold_dia: Find Optimal Probability Threshold

In E2E: Ensemble Learning Framework for Diagnostic and Prognostic Modeling

Find Optimal Probability Threshold

Description

Determines an optimal probability threshold for binary classification based on maximizing F1-score or Youden's J statistic.

Usage

find_optimal_threshold_dia(
  prob_positive,
  y_true,
  type = c("f1", "youden"),
  pos_class,
  neg_class
)

Arguments

prob_positive	A numeric vector of predicted probabilities for the positive class.
y_true	A factor vector of true class labels.
type	A character string, specifying the optimization criterion: "f1" for F1-score or "youden" for Youden's J statistic (Sensitivity + Specificity - 1).
pos_class	A character string, the label for the positive class.
neg_class	A character string, the label for the negative class.

Value

A numeric value, the optimal probability threshold.

Examples

y_true_ex <- factor(c("Negative", "Positive", "Positive", "Negative", "Positive"),
                    levels = c("Negative", "Positive"))
prob_ex <- c(0.1, 0.8, 0.6, 0.3, 0.9)

# Find threshold maximizing F1-score
opt_f1_threshold <- find_optimal_threshold_dia(
  prob_positive = prob_ex,
  y_true = y_true_ex,
  type = "f1",
  pos_class = "Positive",
  neg_class = "Negative"
)
print(opt_f1_threshold)

# Find threshold maximizing Youden's J
opt_youden_threshold <- find_optimal_threshold_dia(
  prob_positive = prob_ex,
  y_true = y_true_ex,
  type = "youden",
  pos_class = "Positive",
  neg_class = "Negative"
)
print(opt_youden_threshold)

E2E documentation built on Aug. 27, 2025, 1:09 a.m.