diff --git a/neural_network/activation_functions/leaky_rectified_linear_unit.py b/neural_network/activation_functions/leaky_rectified_linear_unit.py new file mode 100644 index 000000000..019086fd9 --- /dev/null +++ b/neural_network/activation_functions/leaky_rectified_linear_unit.py @@ -0,0 +1,39 @@ +""" +Leaky Rectified Linear Unit (Leaky ReLU) + +Use Case: Leaky ReLU addresses the problem of the vanishing gradient. +For more detailed information, you can refer to the following link: +https://en.wikipedia.org/wiki/Rectifier_(neural_networks)#Leaky_ReLU +""" + +import numpy as np + + +def leaky_rectified_linear_unit(vector: np.ndarray, alpha: float) -> np.ndarray: + """ + Implements the LeakyReLU activation function. + + Parameters: + vector (np.ndarray): The input array for LeakyReLU activation. + alpha (float): The slope for negative values. + + Returns: + np.ndarray: The input array after applying the LeakyReLU activation. + + Formula: f(x) = x if x > 0 else f(x) = alpha * x + + Examples: + >>> leaky_rectified_linear_unit(vector=np.array([2.3,0.6,-2,-3.8]), alpha=0.3) + array([ 2.3 , 0.6 , -0.6 , -1.14]) + + >>> leaky_rectified_linear_unit(np.array([-9.2, -0.3, 0.45, -4.56]), alpha=0.067) + array([-0.6164 , -0.0201 , 0.45 , -0.30552]) + + """ + return np.where(vector > 0, vector, alpha * vector) + + +if __name__ == "__main__": + import doctest + + doctest.testmod()