Python scipy.fftpack.fftfreq() Examples

The following are 26 code examples of scipy.fftpack.fftfreq(). You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may also want to check out all available functions/classes of the module scipy.fftpack , or try the search function .
Example #1
Source File: fft.py    From pysteps with BSD 3-Clause "New" or "Revised" License 6 votes vote down vote up 
def get_scipy(shape, fftn_shape=None, **kwargs):
    import numpy.fft as numpy_fft
    import scipy.fftpack as scipy_fft

    # use numpy implementation of rfft2/irfft2 because they have not been
    # implemented in scipy.fftpack
    f = {
        "fft2": scipy_fft.fft2,
        "ifft2": scipy_fft.ifft2,
        "rfft2": numpy_fft.rfft2,
        "irfft2": lambda X: numpy_fft.irfft2(X, s=shape),
        "fftshift": scipy_fft.fftshift,
        "ifftshift": scipy_fft.ifftshift,
        "fftfreq": scipy_fft.fftfreq,
    }
    if fftn_shape is not None:
        f["fftn"] = scipy_fft.fftn
    fft = SimpleNamespace(**f)

    return fft
Example #2
Source File: fft.py    From pysteps with BSD 3-Clause "New" or "Revised" License 6 votes vote down vote up 
def get_numpy(shape, fftn_shape=None, **kwargs):
    import numpy.fft as numpy_fft

    f = {
        "fft2": numpy_fft.fft2,
        "ifft2": numpy_fft.ifft2,
        "rfft2": numpy_fft.rfft2,
        "irfft2": lambda X: numpy_fft.irfft2(X, s=shape),
        "fftshift": numpy_fft.fftshift,
        "ifftshift": numpy_fft.ifftshift,
        "fftfreq": numpy_fft.fftfreq,
    }
    if fftn_shape is not None:
        f["fftn"] = numpy_fft.fftn
    fft = SimpleNamespace(**f)

    return fft
Example #3
Source File: test_spectral.py    From Computable with MIT License 6 votes vote down vote up 
def test_complex(self):
        x = np.zeros(16, np.complex128)
        x[0] = 1.0 + 2.0j
        x[8] = 1.0 + 2.0j
        f, p = welch(x, nperseg=8)
        assert_allclose(f, fftpack.fftfreq(8, 1.0))
        assert_allclose(p, np.array([0.41666667, 0.38194444, 0.55555556,
            0.55555556, 0.55555556, 0.55555556, 0.55555556, 0.38194444]))
Example #4
Source File: test_spectral.py    From GraphicDesignPatternByPython with MIT License 5 votes vote down vote up 
def test_real_twosided(self):
        x = np.zeros(16)
        x[0] = 1
        x[8] = 1
        f, p = welch(x, nperseg=8, return_onesided=False)
        assert_allclose(f, fftpack.fftfreq(8, 1.0))
        q = np.array([0.08333333, 0.07638889, 0.11111111, 0.11111111,
                      0.11111111, 0.11111111, 0.11111111, 0.07638889])
        assert_allclose(p, q, atol=1e-7, rtol=1e-7)
Example #5
Source File: amplify_color.py    From Heart-rate-measurement-using-camera with Apache License 2.0 5 votes vote down vote up 
def temporal_ideal_filter(self,tensor,low,high,fps,axis=0):
        fft=fftpack.fft(tensor,axis=axis)
        frequencies = fftpack.fftfreq(tensor.shape[0], d=1.0 / fps)
        bound_low = (np.abs(frequencies - low)).argmin()
        bound_high = (np.abs(frequencies - high)).argmin()
        fft[:bound_low] = 0
        fft[bound_high:-bound_high] = 0
        fft[-bound_low:] = 0
        iff=fftpack.ifft(fft, axis=axis)
        return np.abs(iff)
Example #6
Source File: test_spectral.py    From GraphicDesignPatternByPython with MIT License 5 votes vote down vote up 
def test_complex_32(self):
        x = np.zeros(16, 'F')
        x[0] = 1.0 + 2.0j
        x[8] = 1.0 + 2.0j
        f, p = csd(x, x, nperseg=8, return_onesided=False)
        assert_allclose(f, fftpack.fftfreq(8, 1.0))
        q = np.array([0.41666666, 0.38194442, 0.55555552, 0.55555552,
                      0.55555558, 0.55555552, 0.55555552, 0.38194442], 'f')
        assert_allclose(p, q, atol=1e-7, rtol=1e-7)
        assert_(p.dtype == q.dtype,
                'dtype mismatch, %s, %s' % (p.dtype, q.dtype))
Example #7
Source File: test_spectral.py    From GraphicDesignPatternByPython with MIT License 5 votes vote down vote up 
def test_real_twosided_32(self):
        x = np.zeros(16, 'f')
        x[0] = 1
        x[8] = 1
        f, p = csd(x, x, nperseg=8, return_onesided=False)
        assert_allclose(f, fftpack.fftfreq(8, 1.0))
        q = np.array([0.08333333, 0.07638889, 0.11111111,
                      0.11111111, 0.11111111, 0.11111111, 0.11111111,
                      0.07638889], 'f')
        assert_allclose(p, q, atol=1e-7, rtol=1e-7)
        assert_(p.dtype == q.dtype)
Example #8
Source File: test_spectral.py    From GraphicDesignPatternByPython with MIT License 5 votes vote down vote up 
def test_complex(self):
        x = np.zeros(16, np.complex128)
        x[0] = 1.0 + 2.0j
        x[8] = 1.0 + 2.0j
        f, p = csd(x, x, nperseg=8, return_onesided=False)
        assert_allclose(f, fftpack.fftfreq(8, 1.0))
        q = np.array([0.41666667, 0.38194444, 0.55555556, 0.55555556,
                      0.55555556, 0.55555556, 0.55555556, 0.38194444])
        assert_allclose(p, q, atol=1e-7, rtol=1e-7)
Example #9
Source File: test_spectral.py    From GraphicDesignPatternByPython with MIT License 5 votes vote down vote up 
def test_integer_twosided(self):
        x = np.zeros(16, dtype=int)
        x[0] = 1
        x[8] = 1
        f, p = csd(x, x, nperseg=8, return_onesided=False)
        assert_allclose(f, fftpack.fftfreq(8, 1.0))
        q = np.array([0.08333333, 0.07638889, 0.11111111, 0.11111111,
                      0.11111111, 0.11111111, 0.11111111, 0.07638889])
        assert_allclose(p, q, atol=1e-7, rtol=1e-7)
Example #10
Source File: test_spectral.py    From GraphicDesignPatternByPython with MIT License 5 votes vote down vote up 
def test_real_twosided(self):
        x = np.zeros(16)
        x[0] = 1
        x[8] = 1
        f, p = csd(x, x, nperseg=8, return_onesided=False)
        assert_allclose(f, fftpack.fftfreq(8, 1.0))
        q = np.array([0.08333333, 0.07638889, 0.11111111, 0.11111111,
                      0.11111111, 0.11111111, 0.11111111, 0.07638889])
        assert_allclose(p, q, atol=1e-7, rtol=1e-7)
Example #11
Source File: test_spectral.py    From GraphicDesignPatternByPython with MIT License 5 votes vote down vote up 
def test_complex_32(self):
        x = np.zeros(16, 'F')
        x[0] = 1.0 + 2.0j
        x[8] = 1.0 + 2.0j
        f, p = welch(x, nperseg=8, return_onesided=False)
        assert_allclose(f, fftpack.fftfreq(8, 1.0))
        q = np.array([0.41666666, 0.38194442, 0.55555552, 0.55555552,
                      0.55555558, 0.55555552, 0.55555552, 0.38194442], 'f')
        assert_allclose(p, q, atol=1e-7, rtol=1e-7)
        assert_(p.dtype == q.dtype,
                'dtype mismatch, %s, %s' % (p.dtype, q.dtype))
Example #12
Source File: test_spectral.py    From GraphicDesignPatternByPython with MIT License 5 votes vote down vote up 
def test_real_twosided_32(self):
        x = np.zeros(16, 'f')
        x[0] = 1
        x[8] = 1
        f, p = welch(x, nperseg=8, return_onesided=False)
        assert_allclose(f, fftpack.fftfreq(8, 1.0))
        q = np.array([0.08333333, 0.07638889, 0.11111111,
                      0.11111111, 0.11111111, 0.11111111, 0.11111111,
                      0.07638889], 'f')
        assert_allclose(p, q, atol=1e-7, rtol=1e-7)
        assert_(p.dtype == q.dtype)
Example #13
Source File: test_spectral.py    From GraphicDesignPatternByPython with MIT License 5 votes vote down vote up 
def test_complex(self):
        x = np.zeros(16, np.complex128)
        x[0] = 1.0 + 2.0j
        x[8] = 1.0 + 2.0j
        f, p = welch(x, nperseg=8, return_onesided=False)
        assert_allclose(f, fftpack.fftfreq(8, 1.0))
        q = np.array([0.41666667, 0.38194444, 0.55555556, 0.55555556,
                      0.55555556, 0.55555556, 0.55555556, 0.38194444])
        assert_allclose(p, q, atol=1e-7, rtol=1e-7)
Example #14
Source File: test_spectral.py    From GraphicDesignPatternByPython with MIT License 5 votes vote down vote up 
def test_integer_twosided(self):
        x = np.zeros(16, dtype=int)
        x[0] = 1
        x[8] = 1
        f, p = welch(x, nperseg=8, return_onesided=False)
        assert_allclose(f, fftpack.fftfreq(8, 1.0))
        q = np.array([0.08333333, 0.07638889, 0.11111111, 0.11111111,
                      0.11111111, 0.11111111, 0.11111111, 0.07638889])
        assert_allclose(p, q, atol=1e-7, rtol=1e-7)
Example #15
Source File: bench_pseudo_diffs.py    From Computable with MIT License 5 votes vote down vote up 
def direct_diff(x,k=1,period=None):
    fx = fft(x)
    n = len(fx)
    if period is None:
        period = 2*pi
    w = fftfreq(n)*2j*pi/period*n
    if k < 0:
        w = 1 / w**k
        w[0] = 0.0
    else:
        w = w**k
    if n > 2000:
        w[250:n-250] = 0.0
    return ifft(w*fx).real
Example #16
Source File: test_spectral.py    From GraphicDesignPatternByPython with MIT License 5 votes vote down vote up 
def test_real_twosided_32(self):
        x = np.zeros(16, 'f')
        x[0] = 1
        f, p = periodogram(x, return_onesided=False)
        assert_allclose(f, fftpack.fftfreq(16, 1.0))
        q = np.ones(16, 'f')/16.0
        q[0] = 0
        assert_allclose(p, q)
        assert_(p.dtype == q.dtype)
Example #17
Source File: test_spectral.py    From GraphicDesignPatternByPython with MIT License 5 votes vote down vote up 
def test_complex(self):
        x = np.zeros(16, np.complex128)
        x[0] = 1.0 + 2.0j
        f, p = periodogram(x, return_onesided=False)
        assert_allclose(f, fftpack.fftfreq(16, 1.0))
        q = 5.0*np.ones(16)/16.0
        q[0] = 0
        assert_allclose(p, q)
Example #18
Source File: test_spectral.py    From GraphicDesignPatternByPython with MIT License 5 votes vote down vote up 
def test_integer_twosided(self):
        x = np.zeros(16, dtype=int)
        x[0] = 1
        f, p = periodogram(x, return_onesided=False)
        assert_allclose(f, fftpack.fftfreq(16, 1.0))
        q = np.ones(16)/16.0
        q[0] = 0
        assert_allclose(p, q)
Example #19
Source File: test_spectral.py    From GraphicDesignPatternByPython with MIT License 5 votes vote down vote up 
def test_real_twosided(self):
        x = np.zeros(16)
        x[0] = 1
        f, p = periodogram(x, return_onesided=False)
        assert_allclose(f, fftpack.fftfreq(16, 1.0))
        q = np.ones(16)/16.0
        q[0] = 0
        assert_allclose(p, q)
Example #20
Source File: test_helper.py    From GraphicDesignPatternByPython with MIT License 5 votes vote down vote up 
def test_definition(self):
        x = [0,1,2,3,4,-4,-3,-2,-1]
        assert_array_almost_equal(9*fftfreq(9),x)
        assert_array_almost_equal(9*pi*fftfreq(9,pi),x)
        x = [0,1,2,3,4,-5,-4,-3,-2,-1]
        assert_array_almost_equal(10*fftfreq(10),x)
        assert_array_almost_equal(10*pi*fftfreq(10,pi),x)
Example #21
Source File: test_spectral.py    From Computable with MIT License 5 votes vote down vote up 
def test_real_twosided(self):
        x = np.zeros(16)
        x[0] = 1
        x[8] = 1
        f, p = welch(x, nperseg=8, return_onesided=False)
        assert_allclose(f, fftpack.fftfreq(8, 1.0))
        assert_allclose(p, np.array([0.08333333, 0.07638889, 0.11111111,
            0.11111111, 0.11111111, 0.11111111, 0.11111111, 0.07638889]))
Example #22
Source File: test_spectral.py    From Computable with MIT License 5 votes vote down vote up 
def test_complex(self):
        x = np.zeros(16, np.complex128)
        x[0] = 1.0 + 2.0j
        f, p = periodogram(x)
        assert_allclose(f, fftpack.fftfreq(16, 1.0))
        q = 5.0*np.ones(16)/16.0
        q[0] = 0
        assert_allclose(p, q)
Example #23
Source File: test_helper.py    From Computable with MIT License 5 votes vote down vote up 
def test_definition(self):
        x = [0,1,2,3,4,-4,-3,-2,-1]
        assert_array_almost_equal(9*fftfreq(9),x)
        assert_array_almost_equal(9*pi*fftfreq(9,pi),x)
        x = [0,1,2,3,4,-5,-4,-3,-2,-1]
        assert_array_almost_equal(10*fftfreq(10),x)
        assert_array_almost_equal(10*pi*fftfreq(10,pi),x)
Example #24
Source File: bench_pseudo_diffs.py    From Computable with MIT License 5 votes vote down vote up 
def direct_shift(x,a,period=None):
    n = len(x)
    if period is None:
        k = fftfreq(n)*1j*n
    else:
        k = fftfreq(n)*2j*pi/period*n
    return ifft(fft(x)*exp(k*a)).real
Example #25
Source File: bench_pseudo_diffs.py    From Computable with MIT License 5 votes vote down vote up 
def direct_hilbert(x):
    fx = fft(x)
    n = len(fx)
    w = fftfreq(n)*n
    w = 1j*sign(w)
    return ifft(w*fx)
Example #26
Source File: bench_pseudo_diffs.py    From Computable with MIT License 5 votes vote down vote up 
def direct_tilbert(x,h=1,period=None):
    fx = fft(x)
    n = len(fx)
    if period is None:
        period = 2*pi
    w = fftfreq(n)*h*2*pi/period*n
    w[0] = 1
    w = 1j/tanh(w)
    w[0] = 0j
    return ifft(w*fx)