Convert digital filter second-order section parameters to zero-pole-gain form
Compute the zeros, poles, and gain of a simple system in second-order section form.
sos = [1 1 1 1 0 -1; -2 3 1 1 10 1]; [z,p,k] = sos2zp(sos)
z = 4×1 complex -0.5000 + 0.8660i -0.5000 - 0.8660i 1.7808 + 0.0000i -0.2808 + 0.0000i
p = 4×1 -1.0000 1.0000 -9.8990 -0.1010
k = -2
sos— Second-order section representation
Second-order section representation, specified as a matrix.
is an L-by-6 matrix
whose rows contain the numerator and denominator coefficients bik and aik of the second-order sections of H(z):
[2 4 2 6 0 2;3 3 0 6 0 0] specifies a third-order
Butterworth filter with normalized 3 dB frequency 0.5π
Complex Number Support: Yes
g— Overall system gain
Overall system gain, specified as a real scalar.
Zeros of the system, returned as a vector.
Poles of the system, returned as a vector.
k— Scalar gain
Scalar gain of the system, returned as a scalar.
sos2zp finds the poles and zeros of each second-order section by