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bundles / scipy 1.17.1 / scipy / signal / _spline / symiirorder2_ic_bwd

built-in

scipy.signal._spline:symiirorder2_ic_bwd

Summary

Compute the (backward) mirror-symmetric boundary conditions for a smoothing IIR filter that is composed of cascaded second-order sections.

Extended Summary

The starting condition returned by this function is computed based on the following transfer function 

                cs
H(z) = -------------------
       (1 - a2 z - a3 z^2)

where 

a2 = (2 r cos omega)
a3 = - r^2
cs = 1 - 2 r cos omega + r^2

Parameters

input : ndarray

The input signal.

r, omega : float

Parameters in the transfer function.

precision : float

Specifies the precision for calculating initial conditions of the recursive filter based on mirror-symmetric input.

Returns

zi : ndarray

The mirror-symmetric initial condition for the forward IIR filter.

Aliases

  • scipy.signal._spline.symiirorder2_ic_bwd