Method csd

lib/matplotlib/axes/_axes.py:8118–8216

r""" Plot the cross-spectral density. The cross spectral density :math:`P_{xy}` by Welch's average periodogram method. The vectors *x* and *y* are divided into *NFFT* length segments. Each segment is detrended by function *detrend* and windowed by function

(self, x, y, NFFT=None, Fs=None, Fc=None, detrend=None,
            window=None, noverlap=None, pad_to=None,
            sides=None, scale_by_freq=None, return_line=None, **kwargs)

    @_preprocess_data(replace_names=["x", "y"], label_namer="y")
    @_docstring.interpd
    def csd(self, x, y, NFFT=None, Fs=None, Fc=None, detrend=None,
            window=None, noverlap=None, pad_to=None,
            sides=None, scale_by_freq=None, return_line=None, **kwargs):
        r"""
        Plot the cross-spectral density.

        The cross spectral density :math:`P_{xy}` by Welch's average
        periodogram method.  The vectors *x* and *y* are divided into
        *NFFT* length segments.  Each segment is detrended by function
        *detrend* and windowed by function *window*.  *noverlap* gives
        the length of the overlap between segments.  The product of
        the direct FFTs of *x* and *y* are averaged over each segment
        to compute :math:`P_{xy}`, with a scaling to correct for power
        loss due to windowing.

        If len(*x*) < *NFFT* or len(*y*) < *NFFT*, they will be zero
        padded to *NFFT*.

        Parameters
        ----------
        x, y : 1-D arrays or sequences
            Arrays or sequences containing the data.

        %(Spectral)s

        %(PSD)s

        noverlap : int, default: 0 (no overlap)
            The number of points of overlap between segments.

        Fc : int, default: 0
            The center frequency of *x*, which offsets the x extents of the
            plot to reflect the frequency range used when a signal is acquired
            and then filtered and downsampled to baseband.

        return_line : bool, default: False
            Whether to include the line object plotted in the returned values.

        Returns
        -------
        Pxy : 1-D array
            The values for the cross spectrum :math:`P_{xy}` before scaling
            (complex valued).

        freqs : 1-D array
            The frequencies corresponding to the elements in *Pxy*.

        line : `~matplotlib.lines.Line2D`
            The line created by this function.
            Only returned if *return_line* is True.

        Other Parameters
        ----------------
        data : indexable object, optional
            DATA_PARAMETER_PLACEHOLDER

        **kwargs
            Keyword arguments control the `.Line2D` properties: