Python windows.hann方法代码示例

# 需要导入模块: from scipy.signal import windows [as 别名]
# 或者: from scipy.signal.windows import hann [as 别名]
def _stft(self, data, inverse=False, length=None):
        """
        Single entrypoint for both stft and istft. This computes stft and istft with librosa on stereo data. The two
        channels are processed separately and are concatenated together in the result. The expected input formats are:
        (n_samples, 2) for stft and (T, F, 2) for istft.
        :param data: np.array with either the waveform or the complex spectrogram depending on the parameter inverse
        :param inverse: should a stft or an istft be computed.
        :return: Stereo data as numpy array for the transform. The channels are stored in the last dimension
        """
        assert not (inverse and length is None)
        data = np.asfortranarray(data)
        N = self._params["frame_length"]
        H = self._params["frame_step"]
        win = hann(N, sym=False)
        fstft = istft if inverse else stft
        win_len_arg = {"win_length": None, "length": length} if inverse else {"n_fft": N}
        n_channels = data.shape[-1]
        out = []
        for c in range(n_channels):
            d = data[:, :, c].T if inverse else data[:, c]
            s = fstft(d, hop_length=H, window=win, center=False, **win_len_arg)
            s = np.expand_dims(s.T, 2-inverse)
            out.append(s)
        if len(out) == 1:
            return out[0]
        return np.concatenate(out, axis=2-inverse) 

# 需要导入模块: from scipy.signal import windows [as 别名]
# 或者: from scipy.signal.windows import hann [as 别名]
def test_basic(self):
        assert_allclose(windows.hann(6, sym=False),
                        [0, 0.25, 0.75, 1.0, 0.75, 0.25])
        assert_allclose(windows.hann(7, sym=False),
                        [0, 0.1882550990706332, 0.6112604669781572,
                         0.9504844339512095, 0.9504844339512095,
                         0.6112604669781572, 0.1882550990706332])
        assert_allclose(windows.hann(6, True),
                        [0, 0.3454915028125263, 0.9045084971874737,
                         0.9045084971874737, 0.3454915028125263, 0])
        assert_allclose(windows.hann(7),
                        [0, 0.25, 0.75, 1.0, 0.75, 0.25, 0]) 

# 需要导入模块: from scipy.signal import windows [as 别名]
# 或者: from scipy.signal.windows import hann [as 别名]
def test_extremes(self):
        # Test extremes of alpha correspond to boxcar and hann
        tuk0 = windows.tukey(100, 0)
        box0 = windows.boxcar(100)
        assert_array_almost_equal(tuk0, box0)

        tuk1 = windows.tukey(100, 1)
        han1 = windows.hann(100)
        assert_array_almost_equal(tuk1, han1) 

# 需要导入模块: from scipy.signal import windows [as 别名]
# 或者: from scipy.signal.windows import hann [as 别名]
def test_invalid_inputs(self):
        # Window is not a float, tuple, or string
        assert_raises(ValueError, windows.get_window, set('hann'), 8)

        # Unknown window type error
        assert_raises(ValueError, windows.get_window, 'broken', 4) 

# 需要导入模块: from scipy.signal import windows [as 别名]
# 或者: from scipy.signal.windows import hann [as 别名]
def test_deprecation():
    if dep_hann.__doc__ is not None:  # can be None with `-OO` mode
        assert_('signal.hann is deprecated' in dep_hann.__doc__)
        assert_('deprecated' not in windows.hann.__doc__) 

# 需要导入模块: from scipy.signal import windows [as 别名]
# 或者: from scipy.signal.windows import hann [as 别名]
def nlfer(signal, pitch, parameters):

    #---------------------------------------------------------------
    # Set parameters.
    #---------------------------------------------------------------
    N_f0_min = np.around((parameters['f0_min']*2/float(signal.new_fs))*pitch.nfft)
    N_f0_max = np.around((parameters['f0_max']/float(signal.new_fs))*pitch.nfft)

    window = hann(pitch.frame_size+2)[1:-1]
    data = np.zeros((signal.size))  #Needs other array, otherwise stride and
    data[:] = signal.filtered     #windowing will modify signal.filtered

    #---------------------------------------------------------------
    # Main routine.
    #---------------------------------------------------------------
    samples = np.arange(int(np.fix(float(pitch.frame_size)/2)),
                        signal.size-int(np.fix(float(pitch.frame_size)/2)),
                        pitch.frame_jump)

    data_matrix = np.empty((len(samples), pitch.frame_size))
    data_matrix[:, :] = stride_matrix(data, len(samples),
                                    pitch.frame_size, pitch.frame_jump)
    data_matrix *= window

    specData = np.fft.rfft(data_matrix, pitch.nfft)

    frame_energy = np.abs(specData[:, int(N_f0_min-1):int(N_f0_max)]).sum(axis=1)
    pitch.set_energy(frame_energy, parameters['nlfer_thresh1'])
    pitch.set_frames_pos(samples) 

# 需要导入模块: from scipy.signal import windows [as 别名]
# 或者: from scipy.signal.windows import hann [as 别名]
def lagged_coherence_1freq(sig, fs, freq, n_cycles):
    """Compute the lagged coherence of a frequency using the hanning-taper FFT method.

    Parameters
    ----------
    sig : 1d array
        Time series.
    fs : float
        Sampling rate, in Hz.
    freq : float
        The frequency at which to estimate lagged coherence.
    n_cycles : float
        Number of cycles at the examined frequency to use to compute lagged coherence.

    Returns
    -------
    float
        The computed lagged coherence value.
    """

    # Determine number of samples to be used in each window to compute lagged coherence
    n_samps = int(np.ceil(n_cycles * fs / freq))

    # Split the signal into chunks
    chunks = split_signal(sig, n_samps)
    n_chunks = len(chunks)

    # For each chunk, calculate the Fourier coefficients at the frequency of interest
    hann_window = hann(n_samps)
    fft_freqs = np.fft.fftfreq(n_samps, 1 / float(fs))
    fft_freqs_idx = np.argmin(np.abs(fft_freqs - freq))

    fft_coefs = np.zeros(n_chunks, dtype=complex)
    for ind, chunk in enumerate(chunks):
        fourier_coef = np.fft.fft(chunk * hann_window)
        fft_coefs[ind] = fourier_coef[fft_freqs_idx]

    # Compute the lagged coherence value
    lcs_num = 0
    for ind in range(n_chunks - 1):
        lcs_num += fft_coefs[ind] * np.conj(fft_coefs[ind + 1])
    lcs_denom = np.sqrt(np.sum(np.abs(fft_coefs[:-1])**2) * np.sum(np.abs(fft_coefs[1:])**2))

    return np.abs(lcs_num / lcs_denom)