matplotlib.pyplot.
csd
(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, hold=None, data=None, **kwargs)¶Plot the crossspectral density.
Call signature:
csd(x, y, NFFT=256, Fs=2, Fc=0, detrend=mlab.detrend_none,
window=mlab.window_hanning, noverlap=0, pad_to=None,
sides='default', scale_by_freq=None, return_line=None, **kwargs)
The cross spectral density 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 , 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 : 1D arrays or sequences
Fs : scalar
window : callable or ndarray
sides : [ ‘default’  ‘onesided’  ‘twosided’ ]
pad_to : integer
NFFT : integer
detrend : {‘default’, ‘constant’, ‘mean’, ‘linear’, ‘none’} or callable
scale_by_freq : boolean, optional
noverlap : integer
Fc : integer
return_line : bool



Returns:  Pxy : 1D array
freqs : 1D array
line : a


Other Parameters:  
**kwargs :

See also
Notes
For plotting, the power is plotted as
for decibels, though P_{xy}
itself
is returned.
References
Bendat & Piersol – Random Data: Analysis and Measurement Procedures, John Wiley & Sons (1986)