Aliasing Frequency

Problem

When a sinusoid of frequency f is sampled at rate fs, it appears as an alias at the frequency closest to f among the shifts by multiples of fs.

Return the folded frequency |f - fs * round(f / fs)|, which always lies in [0, fs/2].

Hint

Aliasing folds frequencies above the Nyquist limit back into the baseband.

case 1

in: [100,60]

expected: 20

case 2

in: [10,100]

expected: 10

case 3

in: [60,100]

expected: 40

case 4

in: [250,100]

expected: 50

case 5

in: [0,50]

expected: 0

Starter codePython

def aliased_frequency(f, fs):
    # Your code here
    pass

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