pzplot (Control System Toolbox)

Compute the pole-zero map of an LTI model and return the plot handle

Syntax

h = pzplot(sys)

h = pzplot(sys1,sys2,...) 
h = pzplot(AX,...)
h = pzplot(..., plotoptions)

Description

h = pzplot(sys) computes the poles and (transmission) zeros of the LTI model sys and plots them in the complex plane. The poles are plotted as x's and the zeros are plotted as o's. It also returns the plot handle h. You can use this handle to customize the plot with the getoptions and setoptions commands. Type

```
help pzoptions 
```

for a list of available plot options.

pzplot(sys1,sys2,...) shows the poles and zeros of multiple LTI models sys1,sys2,... on a single plot. You can specify distinctive colors for each model, as in

```
pzplot(sys1,'r',sys2,'y',sys3,'g') 
```

pzplot(AX,...) plots into the axes with handle AX.

pzplot(..., plotoptions) plots the poles and zeros with the options specified in plotoptions. Type

```
help pzoptions 
```

for more detail.

The function sgrid or zgrid can be used to plot lines of constant damping ratio and natural frequency in the s- or z-plane.

For arrays sys of LTI models, pzmap plots the poles and zeros of each model in the array on the same diagram.

Example

Use the plot handle to change the color of the plot's title.

sys = rss(3,2,2);
h = rlocusplot(sys);
p = getoptions(h); % Get options for plot.
p.Title.Color = [1,0,0]; % Change title color in options.
setoptions(h,p); % Apply options to plot.

See Also
getoptions Get plot options

pzmap Compute the pole-zero map of an LTI model

setoptions Set plot options

pzmap reg