scipy.fftpack.ss_diff

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

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

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

y_j = sinh(j*a*2*pi/period)/sinh(j*b*2*pi/period) * x_j
y_0 = a/b * x_0

Parameters :

x : array_like

The array to take the pseudo-derivative from.

a,b

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

period : float, optional

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

Notes

ss_diff(ss_diff(x,a,b),b,a) == x