bundles / scipy latest / scipy / fftpack / _pseudo_diffs / cs_diff

function

`scipy.fftpack._pseudo_diffs:cs_diff`

source: /scipy/fftpack/_pseudo_diffs.py :279

Signature

   def     cs_diff (    x    ,    a    ,    b    ,    period    =  None   ,    _cache    =  <_thread._local object at 0x0000>     )

Summary

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

Extended Summary

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

y_j = -sqrt(-1)*cosh(j*a*2*pi/period)/sinh(j*b*2*pi/period) * x_j
y_0 = 0

Parameters

x : array_like: The array to take the pseudo-derivative from.
a, b : float: Defines the parameters of the cosh/sinh pseudo-differential operator.
period : float, optional: The period of the sequence. Default period is 2*pi.

Returns

cs_diff : ndarray: Pseudo-derivative of periodic sequence x.

Notes

For even len(x), the Nyquist mode of x is taken as zero.

Aliases

scipy.fftpack.cs_diff