Linear Rate Factor

Problem

Compute the contraction factor of a linearly convergent method.

Return (1 - mu / L) ** t for strong convexity modulus mu, smoothness L, and t iterations. Return 0.0 when L is not positive.

Hint

The condition number mu / L controls how fast the gap shrinks.

case 1

in: [1,4,5]

expected: 0.2373046875

case 2

in: [2,10,10]

expected: 0.10737418240000006

case 3

in: [1,1,3]

expected: 0

case 4

in: [3,4,1]

expected: 0.25

Starter codePython

def linear_rate_factor(mu, L, t):
    # Your code here
    pass

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