def test_raises_when_scale_factors_is_not_a_collection_or_float(self):
sr = SR22050()
band = FrequencyBand(1, sr.nyquist)
scale = MelScale(band, 512)
scale_factors = object()
self.assertRaises(
TypeError,
lambda: morlet_filter_bank(sr, 512, scale, scale_factors))
def test_raises_when_scale_factors_length_does_not_match_scale(self):
sr = SR22050()
band = FrequencyBand(1, sr.nyquist)
scale = MelScale(band, 512)
scale_factors = np.linspace(0.1, 1.0, len(scale) // 2)
self.assertRaises(
ValueError,
lambda: morlet_filter_bank(sr, 512, scale, scale_factors))
def test_dimensions_are_correct(self):
sr = SR22050()
band = FrequencyBand(1, sr.nyquist)
scale = MelScale(band, 128)
scale_factors = np.linspace(0.1, 1.0, len(scale))
filter_bank = morlet_filter_bank(sr, 512, scale, scale_factors)
self.assertEqual((128, 512), filter_bank.shape)
expected_freq_dimension = FrequencyDimension(scale)
expected_time_dimension = TimeDimension(*sr)
self.assertEqual(expected_freq_dimension, filter_bank.dimensions[0])
self.assertEqual(expected_time_dimension, filter_bank.dimensions[1])
def test_filters_are_normalized(self):
sr = SR22050()
band = FrequencyBand(1, sr.nyquist)
scale = MelScale(band, 128)
scale_factors = np.linspace(0.1, 1.0, len(scale))
filter_bank = morlet_filter_bank(sr,
512,
scale,
scale_factors,
normalize=True)
norms = np.linalg.norm(filter_bank, axis=-1)
np.testing.assert_allclose(norms, 1.0, rtol=1e-6)