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# scipy.fftpack.tilbert

`scipy.fftpack.``tilbert`(x, h, period=None, _cache={})

  tilbert(x, h, period=2*pi) -> y

  Return h-Tilbert transform of a periodic sequence x.

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

  > y_j = sqrt(-1)*coth(j*h*2*pi/period) * x_j y_0 = 0

  Input:
    h
      Defines the parameter of the Tilbert transform.
    period
      The assumed period of the sequence. Default period is 2*pi.
  Notes:
    If sum(x,axis=0)==0 and n=len(x) is odd then
      tilbert(itilbert(x)) == x
    If 2*pi*h/period is approximately 10 or larger then numerically
      tilbert == hilbert

    (theoretically oo-Tilbert == Hilbert). For even len(x), the Nyquist mode of x is taken zero.

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