scipy.signal.symiirorder2

scipy.signal.symiirorder2()

symiirorder2(input, r, omega {, precision}) -> output

Description:

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

Inputs:

input – the input signal. r, omega – parameters in the transfer function. precision – specifies the precision for calculating initial conditions

of the recursive filter based on mirror-symmetric input.

Output:

output – filtered signal.