Gradient Clipping

Problem

Clip gradients by global L2 norm. If the norm of the gradient vector exceeds max_norm, scale it down to exactly max_norm; otherwise return it unchanged.

Empty input returns [].

Hint

Compute the vector norm once and scale every component by the same factor.

Test cases

case 1

in: [[3,4],5]

expected: [3,4]

case 2

in: [[3,4],2.5]

expected: [1.5,2]

case 3

in: [[0,0],1]

expected: [0,0]

case 4

in: [[6,8],5]

expected: [3,4]

case 5

in: [[],1]

expected: []

Starter codePython

import math
def clip_gradients(grads, max_norm):
    # Your code here
    pass

5 test cases · run your code against them in the editor