def test_harmonic_to_sinusoidal_removes_nyquist_harmonics(self):
f0_hz = np.asarray([50, 3001, 4001, 3001, 50])[np.newaxis, :,
np.newaxis]
orig_harm_amps = np.ones(shape=(1, 5, 3))
harm_amps = orig_harm_amps / np.sum(
orig_harm_amps, axis=-1, keepdims=True)
amps, sin_freqs = core.harmonic_to_sinusoidal(10, harm_amps, f0_hz)
sin_freqs = np.squeeze(sin_freqs)
f0_hz = np.squeeze(f0_hz)
expected_amps = orig_harm_amps * 10
# f1 > nyquist
expected_amps[:, 2, 1] = 0
# f2 > nyquist
expected_amps[:, 1:4, 2] = 0
# normalize
expected_amps[:, 0] /= 3
expected_amps[:, 1] /= 2
expected_amps[:, 3] /= 2
expected_amps[:, 4] /= 3
self.assertAllClose(amps[..., 0], expected_amps[..., 0])
self.assertAllClose(amps[..., 1], expected_amps[..., 1])
self.assertAllClose(amps[..., 2], expected_amps[..., 2])
self.assertAllClose(sin_freqs[..., 0], f0_hz)
self.assertAllClose(sin_freqs[..., 1], f0_hz * 2)
self.assertAllClose(sin_freqs[..., 2], f0_hz * 3)
def test_harmonic_to_sinusoidal(self): f0_hz = core.midi_to_hz([80, 81, 82, 81, 80])[np.newaxis, :, np.newaxis] harm_amps = np.ones(shape=(1, 5, 3)) harm_amps /= np.sum(harm_amps, axis=-1, keepdims=True) amps, sin_freqs = core.harmonic_to_sinusoidal(10, harm_amps, f0_hz) sin_freqs = np.squeeze(sin_freqs) f0_hz = np.squeeze(f0_hz) self.assertAllClose(amps, harm_amps * 10) self.assertAllClose(sin_freqs[..., 0], f0_hz) self.assertAllClose(sin_freqs[..., 1], f0_hz * 2) self.assertAllClose(sin_freqs[..., 2], f0_hz * 3)
def test_harmonic_to_sinusoidal_removes_nyquist_f0(self): f0_hz = np.asarray([200, 400, 8001])[np.newaxis, :, np.newaxis] harm_amps = np.ones(shape=(1, 3, 3)) harm_amps /= np.sum(harm_amps, axis=-1, keepdims=True) amps, sin_freqs = core.harmonic_to_sinusoidal(10, harm_amps, f0_hz) sin_freqs = np.squeeze(sin_freqs) f0_hz = np.squeeze(f0_hz) expected_amps_f0 = harm_amps[..., 0] * 10 expected_amps_f0[:, 2] = 0 self.assertAllClose(amps[..., 0], expected_amps_f0) self.assertAllClose(sin_freqs[..., 0], f0_hz) self.assertAllClose(sin_freqs[..., 1], f0_hz * 2) self.assertAllClose(sin_freqs[..., 2], f0_hz * 3)