def testCutFFTDCArtifacts(self):
x = np.linspace(
100, 199, 100
) # Must not be equal to array index (so we check the fn doesnt just return indices)
# Generate down/up slope; minimum at 10
y = np.linspace(0, 100, 100)
y[:10] = np.linspace(100, 0, 10)
fft = FFT(x, y)
# Insert artificial peak
self.assertEqual(fft.cut_dc_artifacts(return_idx=True), 10)
def testDominantFrequency(self):
x = np.linspace(
100, 199, 100
) # Must not be equal to array index (so we check the fn doesnt just return indices)
y = np.random.random_sample(100)
# Insert artificial peak
y[32] = 8.0
fft = FFT(x, y)
self.assertEqual(fft.dominant_frequency(), 132)
# Check with frequency range
self.assertEqual(fft.dominant_frequency(low=100.0, high=140.0), 132)
def testCutDCArtifactsNoMinimum(self):
# No minimum --> should return original array
x = np.linspace(100, 1, 100)
y = np.linspace(500, 5, 100)
fft = FFT(x, y).cut_dc_artifacts()
self.assertEqual(fft.frequencies.shape, x.shape)
self.assertEqual(fft.amplitudes.shape, y.shape)
assert_allclose(fft.frequencies, x)
assert_allclose(fft.amplitudes, y)
# Check returned index
self.assertEqual(FFT(x, y).cut_dc_artifacts(return_idx=True), 0)
def testNoneLimit(self):
arr = np.arange(0.0, 10.0)
# Low = None
result = FFT(arr, arr + 1.0, None)[:5.0]
desired = np.asarray([1.0, 2.0, 3.0, 4.0, 5.0])
assert_allclose(result.frequencies, desired - 1.0)
assert_allclose(result.amplitudes, desired)
# High = None
result = FFT(arr, arr + 1.0, None)[5.0:]
desired = np.asarray([6.0, 7.0, 8.0, 9.0, 10.0])
assert_allclose(result.frequencies, desired - 1.0)
assert_allclose(result.amplitudes, desired)
def testTupleUnpacking(self):
"Test tuple unpacking for FFT inlining"
arr = np.arange(0.0, 10.0)
result = FFT(arr, arr + 1.0, None)[1.0:5.5]
desired = np.asarray([2.0, 3.0, 4.0, 5.0, 6.0])
assert_allclose(result.frequencies, desired - 1.0)
assert_allclose(result.amplitudes, desired)
def testGeneric(self):
arr = np.arange(0.0, 10.0)
result = FFT(arr, arr + 1.0, None)[1.0:5.5]
desired = np.asarray([2.0, 3.0, 4.0, 5.0, 6.0])
assert_allclose(result.frequencies, desired - 1.0)
assert_allclose(result.amplitudes, desired)
def test_find_closest_value_angle(self):
fftx = np.asarray([1, 2, 3, 4, 5])
fft = FFT(fftx, fftx * 2, fftx * 3)
self.assertEqual((1, 2, 3), fft.closest_value(0.))
def test_find_closest_frequency(self):
fftx = np.asarray([1, 2, 3, 4, 5])
fft = FFT(fftx, fftx * 2)
self.assertEqual(1, fft.closest_frequency(0.))
def testAmplitudeIntegral(self):
fft = FFT(np.arange(4), np.asarray([2, 3, 4, 5]), None)
assert_almost_equal(fft.amplitude_integral(), sum(fft.amplitudes) / 3.)
assert_almost_equal(fft.amplitude_integral(low=1., high=2.01), 3 + 4)
def test_find_closest_value_noangle(self):
fftx = np.asarray([1, 2, 3, 4, 5])
fft = FFT(fftx, fftx * 2)
assert_equal((1, 2, None), fft.closest_value(0.))