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Legend Properties

Control legend appearance and behavior

Legend properties control the appearance and behavior of a Legend object. By changing property values, you can modify certain aspects of the legend. Use dot notation to refer to a particular object and property:

plot(rand(3))
lgd = legend('a','b','c');
c = lgd.TextColor;
lgd.TextColor = 'red';

Appearance

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Text color, specified as an RGB triplet or one of the color options listed in the table. The default color is black with an RGB triplet value of [0 0 0].

For a custom color, specify an RGB triplet. An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1]; for example, [0.4 0.6 0.7]. Alternatively, you can specify some common colors by name. This table lists the long and short color name options and the equivalent RGB triplet values.

OptionDescriptionEquivalent RGB Triplet
'red' or 'r'Red[1 0 0]
'green' or 'g'Green[0 1 0]
'blue' or 'b'Blue[0 0 1]
'yellow' or 'y'Yellow[1 1 0]
'magenta' or 'm'Magenta[1 0 1]
'cyan' or 'c'Cyan[0 1 1]
'white' or 'w'White[1 1 1]
'black' or 'k'Black[0 0 0]
'none'No colorNot applicable

Example: [0 0 0.5]

Example: 'blue'

Background color, specified as an RGB triplet or one of the color options listed in the table. The default value of [1 1 1] corresponds to white.

For a custom color, specify an RGB triplet. An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1]; for example, [0.4 0.6 0.7]. Alternatively, you can specify some common colors by name. This table lists the long and short color name options and the equivalent RGB triplet values.

OptionDescriptionEquivalent RGB Triplet
'red' or 'r'Red[1 0 0]
'green' or 'g'Green[0 1 0]
'blue' or 'b'Blue[0 0 1]
'yellow' or 'y'Yellow[1 1 0]
'magenta' or 'm'Magenta[1 0 1]
'cyan' or 'c'Cyan[0 1 1]
'white' or 'w'White[1 1 1]
'black' or 'k'Black[0 0 0]
'none'No colorNot applicable

Example: legend({'A','B'},'Color','y')

Example: legend({'A','B'},'Color',[0.8 0.8 1])

Display of box outline, specified as one of these values:

  • 'on' — Display the box around the legend.

  • 'off' — Do not display the box around the legend.

Example: legend({'A','B'},'Box','off')

Color of box outline, specified as an RGB triplet or one of the color options listed in the table. The default value of [0.15 0.15 0.15] corresponds to dark gray.

For a custom color, specify an RGB triplet. An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1]; for example, [0.4 0.6 0.7]. Alternatively, you can specify some common colors by name. This table lists the long and short color name options and the equivalent RGB triplet values.

OptionDescriptionEquivalent RGB Triplet
'red' or 'r'Red[1 0 0]
'green' or 'g'Green[0 1 0]
'blue' or 'b'Blue[0 0 1]
'yellow' or 'y'Yellow[1 1 0]
'magenta' or 'm'Magenta[1 0 1]
'cyan' or 'c'Cyan[0 1 1]
'white' or 'w'White[1 1 1]
'black' or 'k'Black[0 0 0]
'none'No colorNot applicable

Example: legend({'A','B'},'EdgeColor',[0 1 0])

Width of box outline, specified as a positive value in point units. One point equals 1/72 inch.

Example: 1.5

Location and Size

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Location with respect to the axes, specified as one of the location values listed in this table.

ValueDescription
'north'Inside top of axes
'south'Inside bottom of axes
'east'Inside right of axes
'west'Inside left of axes
'northeast'Inside top-right of axes (default for 2-D axes)
'northwest'Inside top-left of axes
'southeast'Inside bottom-right of axes
'southwest'Inside bottom-left of axes
'northoutside'Above the axes
'southoutside'Below the axes
'eastoutside'To the right of the axes
'westoutside'To the left of the axes
'northeastoutside'Outside top-right corner of the axes (default for 3-D axes)
'northwestoutside'Outside top-left corner of the axes
'southeastoutside'Outside bottom-right corner of the axes
'southwestoutside'Outside bottom-left corner of the axes
'best'Inside axes where least conflict with data in plot
'bestoutside'To the right of the axes
'none'Determined by Position property. Use the Position property to specify a custom location.

Example: legend('Location','northeastoutside')

Orientation, specified as one of these values:

  • 'vertical' — Stack the legend items vertically.

  • 'horizontal' — List the legend items side-by-side.

Example: legend('Orientation','horizontal')

Custom location and size, specified as a four-element vector of the form [left bottom width height]. The first two values, left and bottom, specify the distance from the lower left corner of the figure to the lower left corner of the legend. The last two values, width and height, specify the legend dimensions. The Units property determines the position units.

If you specify the Position property, then MATLAB® automatically changes the Location property to 'none'.

Example: legend({'A','B'},'Position',[0.2 0.6 0.1 0.2])

Position units, specified as one of the values in this table.

UnitsDescription
'normalized' (default)Normalized with respect to the container, which is usually the figure. The lower left corner of the figure maps to (0,0) and the upper right corner maps to (1,1).
'inches'Inches.
'centimeters'Centimeters.
'characters'Based on the default system font character size.
  • Character width = width of letter x.

  • Character height = distance between the baselines of two lines of text.

'points'Points. One point equals 1/72 inch.
'pixels'

Pixels.

Starting in R2015b, distances in pixels are independent of your system resolution on Windows® and Macintosh systems:

  • On Windows systems, a pixel is 1/96th of an inch.

  • On Macintosh systems, a pixel is 1/72nd of an inch.

On Linux® systems, the size of a pixel is determined by your system resolution.

All units are measured from the lower-left corner of the container window.

This property affects the Position property. If you change the units, then it is good practice to return it to its default value after completing your computation to prevent affecting other functions that assume Units is the default value.

If you specify the Position and Units properties as Name,Value pairs when creating the object, then the order of specification matters. If you want to define the position with particular units, then you must set the Units property before the Position property.

Text

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Automatic update of legend items to reflect current status, specified as one of these values:

  • 'on' — Automatically add legend items for new graphics objects added to the axes. Remove legend items for graphics objects deleted from the axes.

  • 'off' — Do not automatically add or delete legend items.

Example: legend({'A','B'},'AutoUpdate','off')

Text for legend labels, specified as a cell array of character vectors or a string array.

Interpretation of text characters, specified as one of these values:

  • 'tex' — Interpret characters using a subset of TeX markup.

  • 'latex' — Interpret characters using LaTeX markup.

  • 'none' — Display literal characters.

TeX Markup

By default, MATLAB supports a subset of TeX markup. Use TeX markup to add superscripts and subscripts, modify the font type and color, and include special characters in the text.

This table lists the supported modifiers with the Interpreter property set to 'tex'. Modifiers remain in effect until the end of the text. Superscripts and subscripts are an exception because they only modify the next character or the characters within the curly braces.

ModifierDescriptionExample
^{ }Superscript'text^{superscript}'
_{ }Subscript'text_{subscript}'
\bfBold font'\bf text'
\itItalic font'\it text'
\slOblique font (usually the same as italic font)'\sl text'
\rmNormal font'\rm text'
\fontname{specifier}Font name — Set specifier as the name of a font family. You can use this in combination with other modifiers.'\fontname{Courier} text'
\fontsize{specifier}Font size — Set specifier as a numeric scalar value in point units to change the font size.'\fontsize{15} text'
\color{specifier}Font color — Set specifer as one of these colors: red, green, yellow, magenta, blue, black, white, gray, darkGreen, orange, or lightBlue.'\color{magenta} text'
\color[rgb]{specifier}Custom font color — Set specifier as a three-element RGB triplet.'\color[rgb]{0,0.5,0.5} text'

This table lists the supported special characters with the Interpreter property set to 'tex'.

Character SequenceSymbolCharacter SequenceSymbolCharacter SequenceSymbol

\alpha

α

\upsilon

υ

\sim

~

\angle

\phi

\leq

\ast

*

\chi

χ

\infty

\beta

β

\psi

ψ

\clubsuit

\gamma

γ

\omega

ω

\diamondsuit

\delta

δ

\Gamma

Γ

\heartsuit

\epsilon

ϵ

\Delta

Δ

\spadesuit

\zeta

ζ

\Theta

Θ

\leftrightarrow

\eta

η

\Lambda

Λ

\leftarrow

\theta

θ

\Xi

Ξ

\Leftarrow

\vartheta

ϑ

\Pi

Π

\uparrow

\iota

ι

\Sigma

Σ

\rightarrow

\kappa

κ

\Upsilon

ϒ

\Rightarrow

\lambda

λ

\Phi

Φ

\downarrow

\mu

µ

\Psi

Ψ

\circ

º

\nu

ν

\Omega

Ω

\pm

±

\xi

ξ

\forall

\geq

\pi

π

\exists

\propto

\rho

ρ

\ni

\partial

\sigma

σ

\cong

\bullet

\varsigma

ς

\approx

\div

÷

\tau

τ

\Re

\neq

\equiv

\oplus

\aleph

\Im

\cup

\wp

\otimes

\subseteq

\oslash

\cap

\in

\supseteq

\supset

\lceil

\subset

\int

\cdot

·

\o

ο

\rfloor

\neg

¬

\nabla

\lfloor

\times

x

\ldots

...

\perp

\surd

\prime

´

\wedge

\varpi

ϖ

\0

\rceil

\rangle

\mid

|

\vee

\langle

\copyright

©

LaTeX Markup

To use LaTeX markup, set the Interpreter property to 'latex'. Use dollar symbols around the text, for example, use '$\int_1^{20} x^2 dx$' for inline mode or '$$\int_1^{20} x^2 dx$$' for display mode.

The displayed text uses the default LaTeX font style. The FontName, FontWeight, and FontAngle properties do not have an effect. To change the font style, use LaTeX markup.

The maximum size of the text that you can use with the LaTeX interpreter is 1200 characters. For multiline text, this reduces by about 10 characters per line.

For more information about the LaTeX system, see The LaTeX Project website at http://www.latex-project.org/.

Legend title, returned as a legend text object. To add a legend title, set the String property of the legend text object. To change the title appearance, such as the font style or color, set legend text properties. For a list, see Legend Text Properties.

plot(rand(3));
lgd = legend('line 1','line 2','line 3');
lgd.Title.String = 'My Legend Title';
lgd.Title.FontSize = 12;

Alternatively, use the title function to add a title and control the appearance.

plot(rand(3));
lgd = legend('line 1','line 2','line 3');
title(lgd,'My Legend Title','FontSize',12)

Font Style

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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.

Note

The 'oblique' value has been removed. Use 'italic' instead.

Font name, specified as the name of the font to use or 'FixedWidth'. To display and print properly, the font name must be a font that your system supports. The default font depends on the specific operating system and locale.

To use a fixed-width font that looks good in any locale, use 'FixedWidth'. The 'FixedWidth' value relies on the root FixedWidthFontName property. Setting the root FixedWidthFontName property causes an immediate update of the display to use the new font.

Example: 'Cambria'

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.

If you change the axes font size, then MATLAB automatically sets the font size of the Legend object to 90% of the axes font size. If you manually set the Legend object font size, then changing the axes font size does not affect the Legend object.

Thickness of the text characters, specified as one of these values:

  • 'normal' — Default weight as defined by the particular font

  • 'bold' — Thicker character outlines than normal

MATLAB uses the FontWeight property to select a font from those available on your system. Not all fonts have a bold font weight. Therefore, specifying a bold font weight still can result in the normal font weight.

Note

The 'light' and 'demi' font weight values have been removed. Use 'normal' instead.

Visibility

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State of visibility, specified as one of these values:

  • 'on' — Display the object.

  • 'off' — Hide the object without deleting it. You still can access the properties of an invisible object.

Identifiers

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This property is read-only.

Type of graphics object, returned as 'legend'. Use this property to find all objects of a given type within a plotting hierarchy.

Tag to associate with the object, specified as a character vector or string.

Use this property to find objects in a hierarchy. For example, you can use the findobj function to find objects that have a specific Tag property value.

Example: 'January Data'

Data to associate with the object, specified as any MATLAB data, for example, a scalar, vector, matrix, cell array, character array, table, or structure. MATLAB does not use this data.

To associate multiple sets of data or to attach a field name to the data, use the getappdata and setappdata functions.

Example: 1:100

Parent/Child

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Parent, specified as a Figure object, Panel object, or a Tab object.

The Legend object must have the same parent as the associated axes. If you change the parent of the associated axes, then the Legend object automatically updates to use the same parent.

The object has no children. You cannot set this property.

Visibility of the object handle in the Children property of the parent, specified as one of these values:

  • 'on' — Object handle is always visible.

  • 'off' — Object handle is invisible at all times. This option is useful for preventing unintended changes to the UI by another function. Set the HandleVisibility to 'off' to temporarily hide the handle during the execution of that function.

  • 'callback' — Object handle is visible from within callbacks or functions invoked by callbacks, but not from within functions invoked from the command line. This option blocks access to the object at the command line, but allows callback functions to access it.

If the object is not listed in the Children property of the parent, then functions that obtain object handles by searching the object hierarchy or querying handle properties cannot return it. This includes get, findobj, gca, gcf, gco, newplot, cla, clf, and close.

Hidden object handles are still valid. Set the root ShowHiddenHandles property to 'on' to list all object handles regardless of their HandleVisibility property setting.

Interactive Control

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Callback that executes when you click legend items, specified as one of these values:

  • Function handle. For example, @myCallback.

  • Cell array containing a function handle and additional arguments. For example, {@myCallback,arg3}.

  • Character vector that is a valid MATLAB command or function, which is evaluated in the base workspace (not recommended).

If you specify this property using a function handle, then MATLAB passes the Legend object and an event data structure as the first and second input arguments to the function. This table describes the fields in the event data structure.

Event Data Structure Fields

FieldDescription
PeerChart object associated with the clicked legend item.
RegionRegion of legend item clicked, returned as either 'icon' or 'label'.
SelectionType

Type of click, returned as one of these values:

  • 'normal' — Single-click left mouse button

  • 'extend'Shift + single-click left mouse button

  • 'open' — Double-click any mouse button

  • 'alt' — Single-click right mouse button, both mouse buttons (Windows and Mac), or middle mouse button (Mac and Linux). If the UIContextMenu property contains a valid context menu (which is the default), then this type of click opens the context menu instead of triggering the ItemHitFcn callback.

SourceLegend object.
EventNameEvent name, 'ItemHit'.

For an example using this property, see Create Interactive Legends Using Callbacks.

Note

If you set the ButtonDownFcn property, then the ItemHitFcn property is disabled.

Mouse-click callback, specified as one of these values:

  • Function handle

  • Cell array containing a function handle and additional arguments

  • Character vector that is a valid MATLAB command or function, which is evaluated in the base workspace (not recommended)

Use this property to execute code when you click the object. If you specify this property using a function handle, then MATLAB passes two arguments to the callback function when executing the callback:

  • Clicked object — You can access properties of the clicked object from within the callback function.

  • Event data — This argument is empty for this property. Replace it with the tilde character (~) in the function definition to indicate that this argument is not used.

For more information on how to use function handles to define callback functions, see Callback Definition.

Note

If the PickableParts property is set to 'none' or if the HitTest property is set to 'off', then this callback does not execute.

Context menu, specified as a ContextMenu object. Use this property to display a context menu when you right-click the object. Create the context menu using the uicontextmenu function.

Note

If the PickableParts property is set to 'none' or if the HitTest property is set to 'off', then the context menu does not appear.

Selection state, specified as one of these values:

  • 'on' — Selected. If you click the object when in plot edit mode, then MATLAB sets its Selected property to 'on'. If the SelectionHighlight property also is set to 'on', then MATLAB displays selection handles around the object.

  • 'off' — Not selected.

Display of selection handles when selected, specified as one of these values:

  • 'on' — Display selection handles when the Selected property is set to 'on'.

  • 'off' — Never display selection handles, even when the Selected property is set to 'on'.

Callback Execution Control

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Ability to capture mouse clicks, specified as one of these values:

  • 'visible' — Can capture mouse clicks when visible. The Visible property must be set to 'on' and you must click a part of the Legend object that has a defined color. You cannot click a part that has an associated color property set to 'none'. The HitTest property determines if the Legend object responds to the click or if an ancestor does.

  • 'none' — Cannot capture mouse clicks. Clicking the Legend object passes the click to the object below it in the current view of the figure window. The HitTest property of the Legend object has no effect.

Response to captured mouse clicks, specified as one of these values:

  • 'on' — Trigger the ButtonDownFcn callback of the Legend object. If you have defined the UIContextMenu property, then invoke the context menu.

  • 'off' — Trigger the callbacks for the nearest ancestor of the Legend object that has:

    • The HitTest property set to 'on'

    • The PickableParts property set to a value that enables the ancestor to capture mouse clicks.

Note

The PickableParts property determines if the Legend object can capture mouse clicks. If it cannot, then the HitTest property has no effect.

Callback interruption, specified as 'off' or 'on'. The Interruptible property determines if a running callback can be interrupted.

There are two callback states to consider:

  • The running callback is the currently executing callback.

  • The interrupting callback is a callback that tries to interrupt the running callback.

Whenever MATLAB invokes a callback, that callback attempts to interrupt a running callback. The Interruptible property of the object owning the running callback determines if interruption is allowed. There are two possible values:

  • 'off' — The running callback cannot be interrupted. MATLAB finishes executing the running callback without any interruptions. The BusyAction property of the object owning the interrupting callback determines if it is discarded or put in the queue.

  • 'on' — The running callback can be interrupted. Interruption occurs at the next point where MATLAB processes the queue, such as when there is a drawnow, figure, getframe, waitfor, or pause command.

    • If the running callback contains one of these commands, then MATLAB stops the execution of the callback at this point and executes the interrupting callback. MATLAB resumes executing the running callback when the interrupting callback completes.

    • If the running callback does not contain one of these commands, then MATLAB finishes executing the callback without interruption.

Callback queuing specified as 'queue' or 'cancel'. The BusyAction property determines how MATLAB handles the execution of interrupting callbacks.

There are two callback states to consider:

  • The running callback is the currently executing callback.

  • The interrupting callback is a callback that tries to interrupt the running callback.

Whenever MATLAB invokes a callback, that callback attempts to interrupt a running callback. The Interruptible property of the object owning the running callback determines if interruption is allowed. If interruption is not allowed, then the BusyAction property of the object owning the interrupting callback determines if it is discarded or put in the queue.

If a callback of the Legend object tries to interrupt a running callback that cannot be interrupted, then the BusyAction property determines if it is discarded or put in the queue. Specify the BusyAction property as one of these values:

  • 'queue' — Put the interrupting callback in a queue to be processed after the running callback finishes execution. This is the default behavior.

  • 'cancel' — Discard the interrupting callback.

Creation and Deletion Control

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Creation callback, specified as one of these values:

  • Function handle

  • Cell array containing a function handle and additional arguments

  • Character vector that is a valid MATLAB command or function, which is evaluated in the base workspace (not recommended)

Use this property to execute code when you create the object. MATLAB executes the callback after creating the object and setting all of its properties. Setting the CreateFcn property on an existing object has no effect. To have an effect, you must specify the CreateFcn property during object creation. One way to specify the property during object creation is to set the default property value for the object. See Default Property Values for more information.

If you specify this callback using a function handle, then MATLAB passes two arguments to the callback function when executing the callback:

  • Created object — You can access properties of the object from within the callback function. You also can access the object through the CallbackObject property of the root, which can be queried using the gcbo function.

  • Event data — This argument is empty for this property. Replace it with the tilde character (~) in the function definition to indicate that this argument is not used.

For more information on how to use function handles to define callback functions, see Callback Definition.

Deletion callback, specified as one of these values:

  • Function handle

  • Cell array containing a function handle and additional arguments

  • Character vector that is a valid MATLAB command or function, which is evaluated in the base workspace (not recommended)

Use this property to execute code when you delete the object MATLAB executes the callback before destroying the object so that the callback can access its property values.

If you specify this callback using a function handle, then MATLAB passes two arguments to the callback function when executing the callback:

  • Deleted object — You can access properties of the object from within the callback function. You also can access the object through the CallbackObject property of the root, which can be queried using the gcbo function.

  • Event data — This argument is empty for this property. Replace it with the tilde character (~) in the function definition to indicate that this argument is not used.

For more information on how to use function handles to define callback functions, see Callback Definition.

This property is read-only.

Deletion status, returned as 'off' or 'on'. MATLAB sets the BeingDeleted property to 'on' when the delete function of the object begins execution (see the DeleteFcn property). The BeingDeleted property remains set to 'on' until the object no longer exists.

Check the value of the BeingDeleted property to verify that the object is not about to be deleted before querying or modifying it.

Introduced in R2014b

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