scipy.signal.symiirorder2¶
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scipy.signal.
symiirorder2
(input, r, omega {, precision}) → output¶ Implement a smoothing IIR filter with mirror-symmetric boundary conditions using a cascade of second-order sections. The second section uses a reversed sequence. This implements the following transfer function:
cs^2 H(z) = --------------------------------------- (1 - a2/z - a3/z^2) (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 : scalar
Parameters in the transfer function.
precision :
Specifies the precision for calculating initial conditions of the recursive filter based on mirror-symmetric input.
Returns: output : ndarray
The filtered signal.