Sigmoid (Vector)

Problem

Apply the logistic sigmoid function element-wise to a list of values: σ(z) = 1 / (1 + exp(-z)).

Handle large positive and negative values without overflow.

Hint

Factor out the stable scalar sigmoid from ml-002.

case 1

in: [[0,0,0]]

expected: [0.5,0.5,0.5]

case 2

in: [[100,-100,0]]

expected: [1,0,0.5]

case 3

in: [[1,2]]

expected: [0.7310585786300049,0.8807970779778823]

Starter codePython

import math
def sigmoid_vector(z):
    # Your code here
    pass

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