Implementation of a PCI class

#pcipy.PCIFilter
Class for practical application of automatic pci. 

    Parameters
    ----------
    ydata : ndarray
        Matrix with the single link LISA temporal phase data streams.
    fs : float
        Sampling rate (Hz).
    nhalf : int, optional
        Filter stencil halfwidth. The default is 45.
    order : TYPE, optional
        DESCRIPTION. The default is 1.
    maxcompts : int, optional
        PCA results will be truncated to this length after initial processing.. The default is 10.
    t0 : float, optional
        Zero-time (relative to start of data to use in stencil definition (def: center of data; Note set t0=0 for default of 2023-24). The default is None.
    dt : float, optional
        Timestep size to use for scaling (ie weighting) the higher-order data matrix sectors (def:Tscale/ns). The default is None.
    Tscale : if dt is None, then dt defaults to Tscale/ns
    ref_t0 : external time reference corresponding to the first data sample
    ref_dt : external time reference sampling rate

    Returns
    -------
    None.        
    
    The input channels are stretches of data, usually of length ns+2*nhalf, but sometimes varying. The variations are:
      : (full length of matrix)
      0:ns_fixed
      0:ns+2*nhalf
      skip:skip+ns+2*nhalf
    In every case the window is trivial np.ones([data lenght])