pzoptions

Options for pole-zero plots

Description

Use the pzoptions command to create a PZOptions object to customize the appearance of pole-zero plots. Use this object to customize the appearance of plots created using pzplot, iopzplot, or rlocusplot (Control System Toolbox) and override the plot preferences for the MATLAB^® session in which you create the pole-zero plot.

The options you specify for a PZOptions object correspond to properties of the PZPlot (Control System Toolbox), IOPZPlot (Control System Toolbox), or RLocusPlot (Control System Toolbox) chart object.

Creation

Syntax

plotoptions = pzoptions

plotoptions = pzoptions("cstprefs")

Description

plotoptions = pzoptions returns a default set of plot options for use with pzplot, iopzplot, and rlocusplot (Control System Toolbox). You can use these options to customize the pole-zero plot appearance using the command line. This syntax is useful when you want to write a script to generate plots that look the same regardless of the preference settings of the MATLAB session in which you run the script.

plotoptions = pzoptions("cstprefs")initializes the plot options with the options you selected in the Control System Toolbox™ and System Identification Toolbox™ preferences editor. For more information about the editor, see Specify Toolbox Preferences for Linear Analysis Plots. This syntax is useful when you want to change a few plot options but otherwise use your default preferences. A script that uses this syntax can generate results that look different when run in a session with different preferences.

Properties

Confidence Region

ConfidenceRegionNumberSD — Number of standard deviations to use to plot the confidence region

1 (default) | scalar

Number of standard deviations to use to plot the confidence region, specified as a scalar. This is applicable to identified models only. This option is ignored by pzplot and rlocusplot.

This option corresponds to the Characteristics.ConfidenceRegion.NumberOfStandardDeviations property of the chart object.

Units

FreqUnits — Frequency units

'rad/s' (default) | 'Hz' | 'rpm' | 'auto' | ...

Frequency units, specified as one of the following values:

• 'Hz'

• 'rad/s'

• 'rpm'

• 'kHz'

• 'MHz'

• 'GHz'

• 'rad/nanosecond'

• 'rad/microsecond'

• 'rad/millisecond'

• 'rad/minute'

• 'rad/hour'

• 'rad/day'

• 'rad/week'

• 'rad/month'

• 'rad/year'

• 'cycles/nanosecond'

• 'cycles/microsecond'

• 'cycles/millisecond'

• 'cycles/hour'

• 'cycles/day'

• 'cycles/week'

• 'cycles/month'

• 'cycles/year'

You can also specify 'auto' which uses frequency 'rad/TimeUnit', where TimeUnit is the TimeUnit property of the input system.

This option corresponds to the FrequencyUnit property of the chart object.

TimeUnits — Time units

'seconds' (default) | 'milliseconds' | 'minutes' | 'auto' | ...

Time units, specified as one of the following values:

• 'nanoseconds'

• 'microseconds'

• 'milliseconds'

• 'seconds'

• 'minutes'

• 'hours'

• 'days'

• 'weeks'

• 'months'

• 'years'

You can also specify 'auto' which uses time units specified in the TimeUnit property of the input system. For multiple systems with different time units, the units of the first system are used.

This option corresponds to the TimeUnit property of the chart object.

Inputs and Outputs

Input and output options are supported only for iopzmap plots.

IOGrouping — Grouping of input-output pairs

'none' (default) | 'inputs' | 'outputs' | 'all'

Grouping of input-output (I/O) pairs, specified as one of the following:

• 'none' — Do not group inputs or outputs.

• 'inputs' — Group only inputs.

• 'outputs' — Group only outputs.

• 'all' — Group all input-output pairs.

This option corresponds to the IOGrouping property of the chart object.

InputLabels — Input label style

structure

Input label style, specified as a structure with the following fields:

• FontSize — Font size, specified as a scalar value greater than zero in point units. The default font size depends on the specific operating system and locale. One point equals 1/72 inch.

• FontWeight — Character thickness, specified as 'Normal' or 'bold'. MATLAB uses the FontWeight property to select a font from those available on your system. Not all fonts have a bold weight. Therefore, specifying a bold font weight can still result in the normal font weight.

• FontAngle — Character slant, specified as 'Normal' or 'italic'. Not all fonts have both font styles. Therefore, the italic font might look the same as the normal font.

• Color — Text color, specified as an RGB triplet. The default color is dark grey with the RGB triplet [0.4,0.4,0.4].

• Interpreter — Text interpreter, specified as one of these values:

  • 'tex' — Interpret characters using a subset of TeX markup. This is the default value of Interpreter.

  • 'latex' — Interpret characters using LaTeX markup.

  • 'none' — Display literal characters.

OutputLabels — Output label style

structure

Output label style, specified as a structure with the following fields:

• FontSize — Font size, specified as a scalar value greater than zero in point units. The default font size depends on the specific operating system and locale. One point equals 1/72 inch.

• FontWeight — Character thickness, specified as 'Normal' or 'bold'. MATLAB uses the FontWeight property to select a font from those available on your system. Not all fonts have a bold weight. Therefore, specifying a bold font weight can still result in the normal font weight.

• FontAngle — Character slant, specified as 'Normal' or ''italic'. Not all fonts have both font styles. Therefore, the italic font might look the same as the normal font.

• Color — Text color, specified as an RGB triplet. The default color is dark grey with the RGB triplet [0.4,0.4,0.4].

• Interpreter — Text interpreter, specified as one of these values:

  • 'tex' — Interpret characters using a subset of TeX markup. This is the default value of Interpreter.

  • 'latex' — Interpret characters using LaTeX markup.

  • 'none' — Display literal characters.

InputVisible — Option to display inputs

{'on'} (default) | {'off'} | cell array

Option to display inputs, specified as {'on'}, {'off'}, or a cell array with multiple elements.

This option corresponds to the InputVisible property of the chart object.

OutputVisible — Option to display outputs

{'on'} (default) | {'off'} | cell array

Option to display outputs, specified as {'on'}, {'off'}, or a cell array with multiple elements.

This option corresponds to the OutputVisible property of the chart object.

Title and Axis Labels

Title — Title text and style

structure

Title text and style, specified as a structure with the following fields:

• String — Label text, specified as a character vector. By default, the plot is titled 'Bode Diagram'.

• FontSize — Font size, specified as a scalar value greater than zero in point units. The default font size depends on the specific operating system and locale. One point equals 1/72 inch.

• FontWeight — Character thickness, specified as 'Normal' or 'bold'. MATLAB uses the FontWeight property to select a font from those available on your system. Not all fonts have a bold weight. Therefore, specifying a bold font weight can still result in the normal font weight.

• FontAngle — Character slant, specified as 'Normal' or 'italic'. Not all fonts have both font styles. Therefore, the italic font might look the same as the normal font.

• Color — Text color, specified as an RGB triplet. The default color is black specified by the RGB triplet [0,0,0].

• Interpreter — Text interpreter, specified as one of these values:

  • 'tex' — Interpret characters using a subset of TeX markup. This is the default value of Interpreter.

  • 'latex' — Interpret characters using LaTeX markup.

  • 'none' — Display literal characters.

This option corresponds to the Title property of the chart object.

XLabel — X-axis label text and style

structure

X-axis label text and style, specified as a structure with the following fields:

• String — Label text, specified as a character vector. By default, the axis is titled based on the frequency units FreqUnits.

• FontSize — Font size, specified as a scalar value greater than zero in point units. The default font size depends on the specific operating system and locale. One point equals 1/72 inch.

• FontWeight — Character thickness, specified as 'Normal' or 'bold'. MATLAB uses the FontWeight property to select a font from those available on your system. Not all fonts have a bold weight. Therefore, specifying a bold font weight can still result in the normal font weight.

• FontAngle — Character slant, specified as 'Normal' or 'italic'. Not all fonts have both font styles. Therefore, the italic font might look the same as the normal font.

• Color — Text color, specified as an RGB triplet. The default color is black specified by the RGB triplet [0,0,0].

• Interpreter — Text interpreter, specified as one of these values:

  • 'tex' — Interpret characters using a subset of TeX markup. This is the default value of Interpreter.

  • 'latex' — Interpret characters using LaTeX markup.

  • 'none' — Display literal characters.

This option corresponds to the XLabel property of the chart object.

YLabel — Y-axis label text and style

structure

Y-axis label text and style, specified as a structure with the following fields:

• String — Label text, specified as a cell array of character vectors. By default, the axis label is a 1x2 cell array with 'Magnitude' and 'Phase'.

• FontSize — Font size, specified as a scalar value greater than zero in point units. The default font size depends on the specific operating system and locale. One point equals 1/72 inch.

• FontWeight — Character thickness, specified as 'Normal' or 'bold'. MATLAB uses the FontWeight property to select a font from those available on your system. Not all fonts have a bold weight. Therefore, specifying a bold font weight can still result in the normal font weight.

• FontAngle — Character slant, specified as 'Normal' or 'italic'. Not all fonts have both font styles. Therefore, the italic font might look the same as the normal font.

• Color — Text color, specified as an RGB triplet. The default color is black specified by the RGB triplet [0,0,0].

• Interpreter — Text interpreter, specified as one of these values:

  • 'tex' — Interpret characters using a subset of TeX markup. This is the default value of Interpreter.

  • 'latex' — Interpret characters using LaTeX markup.

  • 'none' — Display literal characters.

This option corresponds to the YLabel property of the chart object.

TickLabel — Tick label style

structure

Tick label style, specified as a structure with the following fields:

• FontSize — Font size, specified as a scalar value greater than zero in point units. The default font size depends on the specific operating system and locale. One point equals 1/72 inch.

• FontWeight — Character thickness, specified as 'Normal' or 'bold'. MATLAB uses the FontWeight property to select a font from those available on your system. Not all fonts have a bold weight. Therefore, specifying a bold font weight can still result in the normal font weight.

• FontAngle — Character slant, specified as 'Normal' or 'italic'. Not all fonts have both font styles. Therefore, the italic font might look the same as the normal font.

• Color — Text color, specified as an RGB triplet. The default color is black specified by the RGB triplet [0,0,0].

Grid

Grid — Toggle grid display

'off' (default) | 'on'

Toggle grid display on the plot, specified as either 'off' or 'on'.

This option corresponds to the GridVisible property of the chart object.

GridColor — Color of the grid lines

[0.15 0.15 0.15] (default) | RGB triplet

Color of the grid lines, specified as an RGB triplet. The default color is light grey specified by the RGB triplet [0.15 0.15 0.15].

Axis Limits

XLimMode — X-axis limit selection mode

'auto' (default) | 'manual' | cell array

X-axis limit selection mode, specified as one of the following values:

• 'auto' — Enable automatic limit selection, which is based on the total span of the plotted data.

• 'manual' — Manually specify the axis limits. To specify the axis limits, set the XLim option.

This option corresponds to the XLimitsMode property of the chart object.

YLimMode — Y-axis limit selection mode

'auto' (default) | 'manual' | cell array

Selection mode for the y-axis limits, specified as one of these values:

• 'auto' — Enable automatic limit selection, which is based on the total span of the plotted data.

• 'manual' — Manually specify the axis limits. To specify the axis limits, set the YLim option.

This option corresponds to the YLimitsMode property of the chart object.

XLim — X-axis limits

'{[1,10]}' (default) | cell array of two-element vectors of the form [min,max] | cell array

X-axis limits, specified as a cell array of two-element vector of the form [min,max].

This option corresponds to the XLimits property of the chart object.

YLim — Y-axis limits

'{[1,10]}' (default) | cell array of two-element vector of the form [min,max] | cell array

Y-axis limits, specified as a cell array of two-element vector of the form [min,max].

This option corresponds to the YLimits property of the chart object.

Object Functions

iopzplot	Plot pole-zero map for input-output pairs of dynamic system
pzplot	Plot pole-zero map of dynamic system

Examples

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:

$$sys\left(s\right)=\frac{2s^2+5s+1}{s^2+3s+5}.$$

Create the custom option set using pzoptions.

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 x.

Version History

Introduced in R2012a