# pzmap

Pole-zero map of dynamic system

## Syntax

## Description

`[`

returns the system poles and transmission zeros of the dynamic
system model
`p`

,`z`

] = pzmap(`sys`

)`sys`

.

The following figure shows pole-zero maps for a continuous-time (left) and discrete-time (right) linear time-variant model.

In continuous-time systems, all the poles on the complex s-plane must be in the left-half plane (blue region) to ensure stability. The system is marginally stable if distinct poles lie on the imaginary axis, that is, the real parts of the poles are zero.

In discrete-time systems, all the poles in the complex z-plane must lie inside the unit circle (blue region). The system is marginally stable if it has one or more poles lying on the unit circle.

`pzmap(`

plots a pole-zero map for
`sys`

)`sys`

. In the plot, `x`

and
`o`

represent poles and zeros, respectively. For SISO
systems, `pzmap`

plots the system poles and zeros. For MIMO
systems, `pzmap`

plots the system poles and transmission
zeros.

## Examples

## Input Arguments

## Output Arguments

## Tips

Use the functions

`sgrid`

or`zgrid`

to plot lines of constant damping ratio and natural frequency in the*s*- or*z*-plane on the pole-zero plot.For MIMO models,

`pzmap`

displays all system poles and transmission zeros on a single plot. To map poles and zeros for individual input-output pairs, use`iopzmap`

.For additional options to customize the appearance of the pole-zero plot, use

`pzplot`

.

## Version History

**Introduced before R2006a**