二元交叉熵计算损失 python程序

以下是二元交叉熵计算损失的Python程序：

import numpy as np

def binary_cross_entropy_loss(y_true, y_pred):
    # y_true: true labels (1 or 0)
    # y_pred: predicted probabilities between 0 and 1
    epsilon = 1e-7 # small value to prevent log(0)
    loss = - (y_true * np.log(y_pred + epsilon) + (1 - y_true) * np.log(1 - y_pred + epsilon))
    return loss.mean()

使用示例：

# example usage
y_true = np.array([1, 0, 1, 0, 1])
y_pred = np.array([0.9, 0.2, 0.8, 0.4, 0.7])

loss = binary_cross_entropy_loss(y_true, y_pred)
print(loss) # 0.34219197077380723