xrscipy.signal.coherence
- xrscipy.signal.coherence(darray: DataArray, other_darray: DataArray, fs: float = None, seglen: float = None, overlap_ratio: float = 0.5, window: str | tuple | _SupportsArray[dtype[Any]] | _NestedSequence[_SupportsArray[dtype[Any]]] | bool | int | float | complex | bytes | _NestedSequence[bool | int | float | complex | str | bytes] = 'hann', nperseg: int = 256, noverlap: int = None, nfft: int = None, detrend: str | Callable | bool = 'constant', dim: str = None) DataArray
Calculate the coherence as <CSD> / sqrt(<PSD1> * <PSD2>)
- Parameters:
darray (xarray) – Series of measurement values
other_darray (xarray) – Series of measurement values fs : float, optional Sampling frequency of the darray and other_darray (time) series. If not specified, will be calculated it from the sampling step of the specified (or only) dimension.
window (str or tuple or array_like, optional) – Desired window to use. If window is a string or tuple, it is passed to get_window to generate the window values, which are DFT-even by default. See get_window for a list of windows and required parameters. If window is array_like it will be used directly as the window and its length must be nperseg. Defaults to a Hann window.
seglen (float, optional) – Segment length (i.e. nperseg) in units of the used (e.g. time) dimension.
nperseg (int, optional) – Length of each segment. Defaults to None, but if window is str or tuple, is set to 256, and if window is array_like, is set to the length of the window.
noverlap (int, optional) – Number of points to overlap between segments. If None,
noverlap = np.rint(nperseg * overlap_ratio). Defaults to None.overlap_ratio (float, optional) – Used to calculate noverlap, if it is not specified (see above). Defaults to 0.5.
nfft (int, optional) – Length of the FFT used, if a zero padded FFT is desired. If None, the FFT length is nperseg. Defaults to None.
detrend (str or function or False, optional) – Specifies how to detrend each segment. If detrend is a string, it is passed as the type argument to the detrend function. If it is a function, it takes a segment and returns a detrended segment. If detrend is False, no detrending is done. Defaults to ‘constant’.
return_onesided (bool, optional) – If True, return a one-sided spectrum for real data. If False return a two-sided spectrum. Defaults to True, but for complex data, a two-sided spectrum is always returned.
dim (str, optional) – Dimension along which the FFT is computed and sampling step calculated. If the signal is 1D, uses the only dimension, otherwise must be specified.
- Returns:
coh – Coherence of ‘darray’ and ‘other_darray’. It is complex and abs(coh)**2 is the squared magnitude coherohram.
- Return type: