def test_equals(self):
fb1 = FrequencyBand(20, 20000)
scale1 = LinearScale(fb1, 100)
fb2 = FrequencyBand(20, 20000)
scale2 = LinearScale(fb2, 100)
self.assertEqual(scale1, scale2)
def test_not_equal_when_bands_differ(self):
fb1 = FrequencyBand(20, 20000)
scale1 = LinearScale(fb1, 100)
fb2 = FrequencyBand(20, 20000)
scale2 = LinearScale(fb2, 50)
self.assertNotEqual(scale1, scale2)
def test_can_slice_frequency_dim_with_negative_stop_hz(self):
scale = LinearScale(FrequencyBand(0, 100), 10)
arr = ArrayWithUnits(
np.zeros((13, 10)),
[IdentityDimension(), FrequencyDimension(scale)])
sliced = arr[:, :-Hertz(20)]
self.assertEqual((13, 8), sliced.shape)
self.assertEqual(
FrequencyDimension(LinearScale(FrequencyBand(0, 80), 8)),
sliced.dimensions[-1])
def test_from_example(self):
td = TimeDimension(Seconds(1), Seconds(1))
fd = FrequencyDimension(LinearScale(FrequencyBand(20, 22050), 100))
tf = ArrayWithUnits(np.ones((30, 100)), [td, fd])
from_example = ArrayWithUnits.from_example(np.ones((30, 100)), tf)
self.assertEqual(tf.shape, from_example.shape)
self.assertItemsEqual(tf.dimensions, from_example.dimensions)
def test_can_slice_frequency_dim_with_start_and_end_hz(self):
scale = LinearScale(FrequencyBand(0, 100), 10)
arr = ArrayWithUnits(
np.zeros((13, 10)),
[IdentityDimension(), FrequencyDimension(scale)])
sliced = arr[:, Hertz(20):Hertz(80)]
self.assertEqual((13, 7), sliced.shape)
def fft(x, axis=-1, padding_samples=0):
"""
Apply an FFT along the given dimension, and with the specified amount of
zero-padding
Args:
x (ArrayWithUnits): an :class:`~zounds.core.ArrayWithUnits` instance
which has one or more :class:`~zounds.timeseries.TimeDimension`
axes
axis (int): The axis along which the fft should be applied
padding_samples (int): The number of padding zeros to apply along
axis before performing the FFT
"""
if padding_samples > 0:
padded = np.concatenate(
[x, np.zeros((len(x), padding_samples), dtype=x.dtype)], axis=axis)
else:
padded = x
transformed = np.fft.rfft(padded, axis=axis, norm='ortho')
sr = audio_sample_rate(int(Seconds(1) / x.dimensions[axis].frequency))
scale = LinearScale.from_sample_rate(sr, transformed.shape[-1])
new_dimensions = list(x.dimensions)
new_dimensions[axis] = FrequencyDimension(scale)
return ArrayWithUnits(transformed, new_dimensions)
def test_can_invert_frequency_weighting(self):
td = TimeDimension(Seconds(1), Seconds(1))
fd = FrequencyDimension(LinearScale(FrequencyBand(20, 22050), 100))
tf = ArrayWithUnits(np.random.random_sample((90, 100)), [td, fd])
weighted = tf * AWeighting()
inverted = weighted / AWeighting()
np.testing.assert_allclose(tf, inverted)
def test_can_apply_a_weighting_to_time_frequency_representation(self):
td = TimeDimension(Seconds(1), Seconds(1))
fd = FrequencyDimension(LinearScale(FrequencyBand(20, 22050), 100))
tf = ArrayWithUnits(np.ones((90, 100)), [td, fd])
weighting = AWeighting()
result = tf * weighting
self.assertGreater(result[0, -1], result[0, 0])
def test_can_get_weights_from_tf_representation(self):
td = TimeDimension(Seconds(1), Seconds(1))
fd = FrequencyDimension(LinearScale(FrequencyBand(20, 22050), 100))
tf = ArrayWithUnits(np.ones((90, 100)), [td, fd])
weighting = AWeighting()
weights = weighting.weights(tf)
self.assertEqual((100, ), weights.shape)
def test_matches_fftfreq(self):
samplerate = SR44100()
n_bands = 2048
fft_freqs = np.fft.rfftfreq(n_bands, 1 / int(samplerate))
bands = LinearScale.from_sample_rate(samplerate, n_bands // 2)
linear_freqs = np.array([b.start_hz for b in bands])
np.testing.assert_allclose(linear_freqs, fft_freqs[:-1])
def test_can_construct_instance(self):
frequency = Seconds(1)
duration = Seconds(1)
scale = LinearScale(FrequencyBand(20, 22050), 100)
td = TimeDimension(frequency, duration)
fd = FrequencyDimension(scale)
tf = ArrayWithUnits(np.zeros((30, 100)), [td, fd])
self.assertIsInstance(tf, ArrayWithUnits)
def test_not_equal_when_scale_differs(self):
fb1 = FrequencyBand(20, 20000)
scale1 = LinearScale(fb1, 100)
fb2 = FrequencyBand(20, 20000)
scale2 = GeometricScale(20, 20000, 0.01, 100)
self.assertNotEqual(scale1, scale2)
def test_can_use_negative_axis_indices_max(self):
td = TimeDimension(Seconds(1), Seconds(1))
fd = FrequencyDimension(LinearScale(FrequencyBand(20, 22050), 100))
tf = ArrayWithUnits(np.ones((30, 100)), [td, fd])
result = tf.max(axis=-1)
self.assertIsInstance(result, ArrayWithUnits)
self.assertEqual(1, len(result.dimensions))
self.assertEqual((30,), result.shape)
self.assertIsInstance(result.dimensions[0], TimeDimension)
def test_sum_along_frequency_axis(self):
td = TimeDimension(Seconds(1), Seconds(1))
fd = FrequencyDimension(LinearScale(FrequencyBand(20, 22050), 100))
tf = ArrayWithUnits(np.ones((30, 100)), [td, fd])
result = tf.sum(axis=1)
self.assertIsInstance(result, ArrayWithUnits)
self.assertEqual(1, len(result.dimensions))
self.assertEqual((30,), result.shape)
self.assertIsInstance(result.dimensions[0], TimeDimension)
def _process(self, data):
transformed = self._process_raw(data)
sr = audio_sample_rate(data.dimensions[1].samples_per_second)
scale = LinearScale.from_sample_rate(sr, transformed.shape[1])
yield ArrayWithUnits(
transformed,
[data.dimensions[0], FrequencyDimension(scale)])
def _process(self, data):
raw = self._process_raw(data)
sr = audio_sample_rate(
int(data.shape[1] / data.dimensions[0].duration_in_seconds))
scale = LinearScale.from_sample_rate(
sr, data.shape[1], always_even=self.scale_always_even)
yield ArrayWithUnits(
raw,
[data.dimensions[0], FrequencyDimension(scale)])
def test_can_multiply_by_array(self):
frequency = Seconds(1)
duration = Seconds(1)
scale = LinearScale(FrequencyBand(20, 22050), 100)
td = TimeDimension(frequency, duration)
fd = FrequencyDimension(scale)
tf = ArrayWithUnits(np.ones((30, 100)), [td, fd])
result = tf * np.ones(100)
self.assertIsInstance(result, ArrayWithUnits)
np.testing.assert_allclose(tf, result)
def test_can_access_time_slice_and_int_index(self):
tf = ArrayWithUnits(
np.ones((10, 10)),
dimensions=[
TimeDimension(Seconds(1), Seconds(1)),
FrequencyDimension(LinearScale(FrequencyBand(0, 1000), 10))
])
sliced = tf[TimeSlice(start=Seconds(1), duration=Seconds(2)), 0]
self.assertEqual((2,), sliced.shape)
self.assertIsInstance(sliced.dimensions[0], TimeDimension)
def test_can_access_int_index_and_frequency_band(self):
tf = ArrayWithUnits(
np.ones((10, 10)),
dimensions=[
TimeDimension(Seconds(1), Seconds(1)),
FrequencyDimension(LinearScale(FrequencyBand(0, 1000), 10))
])
sliced = tf[0, FrequencyBand(201, 400)]
self.assertEqual((2,), sliced.shape)
self.assertIsInstance(sliced.dimensions[0], FrequencyDimension)
def test_can_slice_frequency_dimension_with_integer_indices(self):
frequency = Seconds(1)
duration = Seconds(1)
scale = LinearScale(FrequencyBand(20, 22050), 100)
td = TimeDimension(frequency, duration)
fd = FrequencyDimension(scale)
tf = ArrayWithUnits(np.zeros((30, 100)), [td, fd])
sliced = tf[:, 10: 20]
self.assertEqual((30, 10), sliced.shape)
self.assertIsInstance(sliced, ArrayWithUnits)
def test_can_use_keepdims_with_sum(self):
td = TimeDimension(Seconds(1), Seconds(1))
fd = FrequencyDimension(LinearScale(FrequencyBand(20, 22050), 100))
tf = ArrayWithUnits(np.ones((30, 100)), [td, fd])
result = tf.sum(axis=-1, keepdims=True)
self.assertIsInstance(result, ArrayWithUnits)
self.assertEqual(2, len(result.dimensions))
self.assertEqual((30, 1), result.shape)
self.assertIsInstance(result.dimensions[0], TimeDimension)
self.assertIsInstance(result.dimensions[1], IdentityDimension)
def _process(self, data):
transformed = dct(data, norm='ortho', axis=self._axis)
sr = audio_sample_rate(
int(data.shape[1] / data.dimensions[0].duration_in_seconds))
scale = LinearScale.from_sample_rate(
sr, transformed.shape[-1], always_even=self.scale_always_even)
yield ArrayWithUnits(
transformed,
[data.dimensions[0], FrequencyDimension(scale)])
def test_raises_if_scale_length_does_not_match_frequency_dimension(self):
frequency = Seconds(1)
duration = Seconds(1)
scale = LinearScale(FrequencyBand(20, 22050), 1000)
td = TimeDimension(frequency, duration)
fd = FrequencyDimension(scale)
self.assertRaises(
ValueError,
lambda: ArrayWithUnits(np.ones((30, 100)), [td, fd]))
def test_can_add_axis_at_end(self):
_id = IdentityDimension()
td = TimeDimension(Seconds(1), Seconds(1))
fd = FrequencyDimension(LinearScale(FrequencyBand(20, 22050), 100))
tf = ArrayWithUnits(np.ones((3, 30, 100)), [_id, td, fd])
tf2 = tf[..., None]
self.assertEqual(4, tf2.ndim)
self.assertIsInstance(tf2.dimensions[0], IdentityDimension)
self.assertIsInstance(tf2.dimensions[1], TimeDimension)
self.assertIsInstance(tf2.dimensions[2], FrequencyDimension)
self.assertIsInstance(tf2.dimensions[3], IdentityDimension)
def test_can_get_all_even_sized_bands(self):
samplerate = SR44100()
scale = LinearScale.from_sample_rate(samplerate,
44100,
always_even=True)
log_scale = GeometricScale(20, 20000, 0.01, 64)
slices = [scale.get_slice(band) for band in log_scale]
sizes = [s.stop - s.start for s in slices]
self.assertTrue(
not any([s % 2 for s in sizes]),
'All slice sizes should be even but were {sizes}'.format(
**locals()))
def test_can_use_tuple_indices_for_first_dimension(self):
tf = ArrayWithUnits(
np.ones((10, 10)),
dimensions=[
TimeDimension(Seconds(1), Seconds(1)),
FrequencyDimension(LinearScale(FrequencyBand(0, 1000), 10))
])
subset = tf[tuple([2, 4, 6]), ...]
self.assertEqual((3, 10), subset.shape)
self.assertIsInstance(subset, ArrayWithUnits)
self.assertIsInstance(subset.dimensions[0], TimeDimension)
self.assertIsInstance(subset.dimensions[1], FrequencyDimension)
def test_ellipsis(self):
scale = LinearScale(FrequencyBand(0, 10000), 100)
arr = ArrayWithUnits(
np.zeros((10, 3, 100)),
[IdentityDimension(),
TimeDimension(Seconds(1)),
FrequencyDimension(scale)])
sliced = arr[..., FrequencyBand(1000, 5000)]
self.assertEqual((10, 3, 41), sliced.shape)
self.assertIsInstance(sliced.dimensions[0], IdentityDimension)
self.assertIsInstance(sliced.dimensions[1], TimeDimension)
self.assertIsInstance(sliced.dimensions[2], FrequencyDimension)
def test_can_slice_freq_dimension_with_freq_band_spanning_bins(self):
frequency = Seconds(1)
duration = Seconds(1)
scale = LinearScale(FrequencyBand(20, 22050), 100)
td = TimeDimension(frequency, duration)
fd = FrequencyDimension(scale)
tf = ArrayWithUnits(np.zeros((30, 100)), [td, fd])
bands = list(scale)
wide_band = FrequencyBand(bands[0].start_hz, bands[9].stop_hz)
sliced = tf[:, wide_band]
self.assertEqual((30, 10), sliced.shape)
self.assertIsInstance(sliced, ArrayWithUnits)
def test_can_iterate_over_time_frequency_representation(self):
tf = ArrayWithUnits(
np.ones((10, 10)),
dimensions=[
TimeDimension(Seconds(1), Seconds(1)),
FrequencyDimension(LinearScale(FrequencyBand(0, 1000), 10))
])
rows = [row for row in tf]
self.assertEqual(10, len(rows))
for row in rows:
self.assertIsInstance(row, ArrayWithUnits)
self.assertIsInstance(row.dimensions[0], FrequencyDimension)
self.assertEqual((10,), row.shape)
def test_scale_is_modified_after_slice(self):
frequency = Seconds(1)
duration = Seconds(1)
scale = LinearScale(FrequencyBand(20, 22050), 100)
td = TimeDimension(frequency, duration)
fd = FrequencyDimension(scale)
tf = ArrayWithUnits(np.zeros((30, 100)), [td, fd])
bands = list(scale)
wide_band = FrequencyBand(bands[0].start_hz, bands[9].stop_hz)
sliced = tf[:, wide_band]
self.assertEqual((30, 10), sliced.shape)
self.assertIsInstance(sliced, ArrayWithUnits)
self.assertLess(sliced.dimensions[1].scale.stop_hz, scale.stop_hz)
self.assertEqual(10, sliced.dimensions[1].scale.n_bands)
