Easy

ReLU Activation

~10 mincode completion

Implement that applies ReLU element-wise.

Examples

Mixed positive and negative values

Input
relu([-3, -1, 0, 1, 3])
Output
[0, 0, 0, 1, 3]

2D array

Input
relu([[1, -1], [2, -2]])
Output
[[1, 0], [2, 0]]

All negative: all zeros

Input
relu([-5, -4, -3, -2, -1])
Output
[0, 0, 0, 0, 0]

Hints

Hint 1

compares elementwise against a scalar or another array.

Hint 2

Reach for np maximum rather than np max.

Requirements

  • z: Scalar or NumPy array

  • Return max(0, z) applied element-wise, same shape as input.

Constraints

  • Allowed library: NumPy only

  • Time limit: 200 ms, Memory: 64 MB

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Where this shows up

~10 min

8 employers weight this skill

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Python
import numpy as np

def relu(z):
    """
    Apply the ReLU activation function element-wise.

    Args:
        z: Scalar or NumPy array

    Returns:
        max(0, z) applied element-wise, same shape as input.
    """
    # YOUR CODE HERE
    pass
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