matlab提供了哪些进行零极点求解的函数

前几天刚碰到这个问题 应该使用minreal 你在matlab里打doc minreal可以看到他的用法如：inreal的用法：sysr = minreal(sys) eliminates uncontrollable or unobservable state in state-space models, or cancels pole-zero pairs in transfer functions or zero-pole-gain models.
Examples
The commands
g = zpk([],1,1)
h = tf([2 1],[1 0])
cloop = inv(1+g*h) * g
produce the nonminimal zero-pole-gain model by typing cloop.
Zero/pole/gain:
s (s-1)
-------------------
(s-1) (s^2 + s + 1)
To cancel the pole-zero pair at s = 1, type
cloop = minreal(cloop)
This command produces the following result.
Zero/pole/gain:
s
-------------
(s^2 + s + 1)

求零极点用zpk函数