Time Encoding Features

Problem

Encode a timestamp with a single seasonal cycle: [sin(2*pi*t/max_period), cos(2*pi*t/max_period)].

Return an empty list when max_period is not positive. The pair places each timestamp on a circle so the encoding wraps smoothly.

Hint

Sinusoidal encodings avoid the discontinuity of raw hour or month numbers.

case 1

in: [0,24]

expected: [0,1]

case 2

in: [6,24]

expected: [1,6.123233995736766e-17]

case 3

in: [12,24]

expected: [1.2246467991473532e-16,-1]

case 4

in: [5,0]

expected: []

Starter codePython

import math
def time_encoding_features(t, max_period):
    # Your code here
    pass

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