Pole-zero plot of dynamic system model with additional plot customization options
pzplot lets you plot pole-zero maps with a broader range of
plot customization options than
pzmap. You can use
pzplot to obtain the plot handle and use it to customize the
plot, such as modify the axes labels, limits and units. You can also use
pzplot to draw a pole-zero plot on an existing set of axes
represented by an axes handle. To customize an existing plot using the plot
Obtain the plot handle
getoptionsto obtain the option set
Update the plot using
setoptionsto modify the required options
For more information, see Customizing Response Plots from the Command Line (Control System Toolbox). To create pole-zero maps with default options or to extract pole-zero data, use
plots the poles and transmission zeros of the dynamic system
h = pzplot(
sys and returns the plot handle
h to the
o indicates poles and zeros
plots the poles and transmission zeros with the options specified in
h = pzplot(...,
plotoptions. For more information on the ways to change
properties of your plots, see Ways to Customize Plots (Control System Toolbox).
Pole-Zero Plot with Custom Plot Title
Plot the poles and zeros of the continuous-time system represented by the following transfer function:
sys = tf([2 5 1],[1 3 5]); h = pzplot(sys); grid on
Turning on the grid displays lines of constant damping ratio (zeta) and lines of constant natural frequency (wn). This system has two real zeros, marked by o on the plot. The system also has a pair of complex poles, marked by x.
Change the color of the plot title. To do so, use the plot handle,
p = getoptions(h); p.Title.Color = [1,0,0]; setoptions(h,p);
Pole-Zero Plot of Multiple Models
For this example, load a 3-by-1 array of transfer function models.
3x1 array of transfer functions. Each model has 1 outputs and 1 inputs.
Plot the poles and zeros of the model array. Define the colors for each model. For this example, use red for the first model, green for the second and blue for the third model in the array.
Pole-Zero Plot with Custom Options
Plot the poles and zeros of the continuous-time system represented by the following transfer function with a custom option set:
Create the custom option set using
plotoptions = pzoptions;
For this example, specify the grid to be visible.
plotoptions.Grid = 'on';
Use the specified options to create a pole-zero map of the transfer function.
h = pzplot(tf([2 5 1],[1 3 5]),plotoptions);
Turning on the grid displays lines of constant damping ratio (zeta) and lines of constant natural frequency (wn). This system has two real zeros, marked by
o on the plot. The system also has a pair of complex poles, marked by
sys — Dynamic system
dynamic system model | model array
Dynamic system, specified as a SISO or MIMO dynamic system model, or an
array of SISO or MIMO dynamic system models. Dynamic systems that you can
use include continuous-time or discrete-time numeric LTI models such as
tf (Control System Toolbox),
zpk (Control System Toolbox), or
ss (Control System Toolbox) models.
sys is a generalized state-space model
genss or an uncertain state-space model
pzplot returns the poles and
transmission zeros of the current or nominal value of
sys is an array of
pzplot plots the poles and zeros of each model in
the array on the same diagram.
LineSpec — Line style, marker, and color
character vector | string
Line style, marker, and color, specified as a character vector or string containing symbols. The symbols can appear in any order. You do not need to specify all three characteristics (line style, marker, and color). For example, if you omit the line style and specify the marker, then the plot shows only the marker and no line.
'--or' is a red dashed line with circle markers
ax — Axes handle
Axes handle, specified as an axes object. If you do not specify the axes
pzplot uses the current axes
gca to plot the poles and zeros of the system.
plotoptions — Pole-zero plot options
Pole-zero plot options, specified as an options object. See
for a list of available plot options.
h — Pole-zero plot options handle
Pole-zero plot options handle, returned as a scalar. Use
h to query and modify properties of your pole-zero
plot. You can use this handle to customize the plot with the
Introduced before R2006a
- Ways to Customize Plots (Control System Toolbox)