Function dft_bins

numpy_ml/preprocessing/dsp.py:276–301

Calc the frequency bin centers for a DFT with `N` coefficients. Parameters ---------- N : int The number of frequency bins in the DFT fs : int The sample rate/frequency of the signal (in Hz). Default is 44000. positive_only : bool Whether to only ret

(N, fs=44000, positive_only=True)

def dft_bins(N, fs=44000, positive_only=True):
    """
    Calc the frequency bin centers for a DFT with `N` coefficients.

    Parameters
    ----------
    N : int
        The number of frequency bins in the DFT
    fs : int
        The sample rate/frequency of the signal (in Hz). Default is 44000.
    positive_only : bool
        Whether to only return the bins for the positive frequency
        terms. Default is True.

    Returns
    -------
    bins : :py:class:`ndarray <numpy.ndarray>` of shape `(N,)` or `(N // 2 + 1,)` if `positive_only`
        The frequency bin centers associated with each coefficient in the
        DFT spectrum
    """
    if positive_only:
        freq_bins = np.linspace(0, fs / 2, 1 + N // 2, endpoint=True)
    else:
        l, r = (1 + (N - 1) / 2, (1 - N) / 2) if N % 2 else (N / 2, -N / 2)
        freq_bins = np.r_[np.arange(l), np.arange(r, 0)] * fs / N
    return freq_bins


def magnitude_spectrum(frames):