MediumCalculusca-338

Softplus Second Derivative Vector

Problem

Softplus has first derivative sigmoid(z), so its second derivative is sigmoid(z) * (1 - sigmoid(z)).

Given the values z, return the second derivative list using a stable sigmoid.

Hint

The second derivative of softplus is the derivative of the sigmoid.

case 1

in: [[0,1,-1]]

expected: [0.25,0.19661193324148185,0.19661193324148185]

case 2

in: [[5,-5]]

expected: [0.006648056670790033,0.0066480566707901555]

case 3

in: [[2,-2]]

expected: [0.10499358540350662,0.1049935854035065]

Starter codePython

def softplus_second_derivative(values):
    # Your code here
    pass

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