MediumCalculusca-174

DFT Leakage Lite

Problem

When a sinusoid lies delta bins away from an integer DFT bin, the peak bin magnitude of a rectangular window of length N is scaled by

L = |sin(pi*delta)| / (N * |sin(pi*delta / N)|)

Return L for N > 0 and delta >= 0, with L = 1.0 when delta is exactly 0.

Hint

This is the Dirichlet kernel magnitude divided by N; it decays away from integer bins.

case 1

in: [8,0]

expected: 1

case 2

in: [8,0.5]

expected: 0.6407288619353766

case 3

in: [16,1]

expected: 0

case 4

in: [4,0.25]

expected: 0.9061274463528879

Starter codePython

def dft_leakage(n, delta):
    # Your code here
    pass

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