scipy.signal.

zpk2tf#

scipy.signal.zpk2tf(z, p, k)[source]#

Return polynomial transfer function representation from zeros and poles

Parameters:
zarray_like

Zeros of the transfer function.

parray_like

Poles of the transfer function.

kfloat

System gain.

Returns:
bndarray

Numerator polynomial coefficients.

andarray

Denominator polynomial coefficients.

Examples

Find the polynomial representation of a transfer function H(s) using its ‘zpk’ (Zero-Pole-Gain) representation.

\[H(z) = 5 \frac { (s - 2)(s - 6) } { (s - 1)(s - 8) }\]
>>> from scipy.signal import zpk2tf
>>> z   = [2,   6]
>>> p   = [1,   8]
>>> k   = 5
>>> zpk2tf(z, p, k)
(   array([  5., -40.,  60.]), array([ 1., -9.,  8.]))