# scipy.fftpack.cc_diff

scipy.fftpack.cc_diff(x, a, b, period=None, _cache={})

  Return (a,b)-cosh/cosh pseudo-derivative of a periodic sequence.

  If x_j and y_j are Fourier coefficients of periodic functions x and y, respectively, then:

      y_j = cosh(j*a*2*pi/period)/cosh(j*b*2*pi/period) * x_j

  Parameters
    x array_like

      The array to take the pseudo-derivative from.

    a,b float

      Defines the parameters of the sinh/sinh pseudo-differential operator.

    period float, optional

      The period of the sequence x. Default is `2*pi`.

  Returns
    cc_diff ndarray

      Pseudo-derivative of periodic sequence x.

  Notes

  `cc_diff(cc_diff(x,a,b),b,a) == x`

scipy.fftpack.ss_diff scipy.fftpack.shift