Fourier Basis Feature Value

Problem

Evaluate a Fourier basis feature: cos(pi * order . state). The order vector holds non-negative integer frequencies, one per state dimension.

Hint

The all-zero order gives the constant feature 1.

case 1

in: [[0.5],[1]]

expected: 6.123233995736766e-17

case 2

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

expected: 1

case 3

in: [[0.25,0.25],[2,2]]

expected: -1

case 4

in: [[0.3],[0]]

expected: 1

Starter codePython

import math
def fourier_feature(state, order):
    # Your code here
    pass

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