# ConstantRegion Properties

Constant region appearance and behavior

Since R2023a

A constant region is a filled area between two x- or y-values in a 1-D plot. Use the `xregion` or `yregion` function to create a constant region. You can modify its appearance and behavior by changing `ConstantRegion` property values.

```xr = xregion(5,10); xr.FaceColor = "green";```

## Location

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Minimum and maximum region values, specified as a two-element vector. The minimum and maximum region values can be defined in either element of the vector. Thus, a value of `[1 5]` and `[5 1]` produce the same result.

To create an unbounded region, specify one of the elements as `Inf` or `-Inf`. (since R2023b)

If either value is a `NaN` value, no region appears in the axes.

#### Example

Create a constant region from `x=5` to `x=10`. Then change the upper bound to `7`.

```xr = xregion(5,10); xr.Value(2) = 7;```

Data Types: `single` | `double` | `int8` | `int16` | `int32` | `int64` | `uint8` | `uint16` | `uint32` | `uint64` | `categorical` | `datetime` | `duration`

Intercept axis, specified as `"x"` or `"y"`. A constant region with an x-intercept is a filled area between two x-values. Similarly, a constant region with a y-intercept is a filled area between two y-values.

Since R2024a

Layer position, specified as `"bottom"` or `"top"`. A value of `"bottom"` displays the `ConstantRegion` object under other items in the axes, such as lines or markers. A value of `"top"` displays the `ConstantRegion` object on top of other items.

Passing a `ConstantRegion` object to the `uistack` function has no effect on its stacking order, nor does reordering the `Children` property of the axes.

## Color and Styling

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Fill color, specified as an RGB triplet, a hexadecimal color code, or a color name.

For a custom color, specify an RGB triplet or a hexadecimal color code.

• 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]```.

• A hexadecimal color code is a string scalar or character vector that starts with a hash symbol (`#`) followed by three or six hexadecimal digits, which can range from `0` to `F`. The values are not case sensitive. Therefore, the color codes `"#FF8800"`, `"#ff8800"`, `"#F80"`, and `"#f80"` are equivalent.

Alternatively, you can specify some common colors by name. This table lists the named color options, the equivalent RGB triplets, and hexadecimal color codes.

Color NameShort NameRGB TripletHexadecimal Color CodeAppearance
`"red"``"r"``[1 0 0]``"#FF0000"`

`"green"``"g"``[0 1 0]``"#00FF00"`

`"blue"``"b"``[0 0 1]``"#0000FF"`

`"cyan"` `"c"``[0 1 1]``"#00FFFF"`

`"magenta"``"m"``[1 0 1]``"#FF00FF"`

`"yellow"``"y"``[1 1 0]``"#FFFF00"`

`"black"``"k"``[0 0 0]``"#000000"`

`"white"``"w"``[1 1 1]``"#FFFFFF"`

`"none"`Not applicableNot applicableNot applicableNo color

Here are the RGB triplets and hexadecimal color codes for the default colors MATLAB® uses in many types of plots.

`[0 0.4470 0.7410]``"#0072BD"`

`[0.8500 0.3250 0.0980]``"#D95319"`

`[0.9290 0.6940 0.1250]``"#EDB120"`

`[0.4940 0.1840 0.5560]``"#7E2F8E"`

`[0.4660 0.6740 0.1880]``"#77AC30"`

`[0.3010 0.7450 0.9330]``"#4DBEEE"`

`[0.6350 0.0780 0.1840]``"#A2142F"`

Control how the `FaceColor` property is set, specified as one of these values:

• `"auto"` — MATLAB controls the value of the `FaceColor` property by using the `SeriesIndex` property of the `ConstantRegion` object and the `ColorOrder` property of the axes.

• `"manual"` — You set the value of the `FaceColor` property directly, or indirectly as a function argument when you create the `ConstantRegion` object.

If you change the value of the `FaceColor` property manually, MATLAB changes the value of the `FaceColorMode` property to `"manual"`.

Boundary line color, specified as an RGB triplet, a hexadecimal color code, or a color name.

For a custom color, specify an RGB triplet or a hexadecimal color code.

• 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]```.

• A hexadecimal color code is a string scalar or character vector that starts with a hash symbol (`#`) followed by three or six hexadecimal digits, which can range from `0` to `F`. The values are not case sensitive. Therefore, the color codes `"#FF8800"`, `"#ff8800"`, `"#F80"`, and `"#f80"` are equivalent.

Alternatively, you can specify some common colors by name. This table lists the named color options, the equivalent RGB triplets, and hexadecimal color codes.

Color NameShort NameRGB TripletHexadecimal Color CodeAppearance
`"red"``"r"``[1 0 0]``"#FF0000"`

`"green"``"g"``[0 1 0]``"#00FF00"`

`"blue"``"b"``[0 0 1]``"#0000FF"`

`"cyan"` `"c"``[0 1 1]``"#00FFFF"`

`"magenta"``"m"``[1 0 1]``"#FF00FF"`

`"yellow"``"y"``[1 1 0]``"#FFFF00"`

`"black"``"k"``[0 0 0]``"#000000"`

`"white"``"w"``[1 1 1]``"#FFFFFF"`

`"none"`Not applicableNot applicableNot applicableNo color

Here are the RGB triplets and hexadecimal color codes for the default colors MATLAB uses in many types of plots.

`[0 0.4470 0.7410]``"#0072BD"`

`[0.8500 0.3250 0.0980]``"#D95319"`

`[0.9290 0.6940 0.1250]``"#EDB120"`

`[0.4940 0.1840 0.5560]``"#7E2F8E"`

`[0.4660 0.6740 0.1880]``"#77AC30"`

`[0.3010 0.7450 0.9330]``"#4DBEEE"`

`[0.6350 0.0780 0.1840]``"#A2142F"`

Fill color transparency, specified as a scalar in the range `[0,1]`. A value of `1` is opaque and `0` is completely transparent. Values between `0` and `1` are partially transparent.

Boundary line transparency, specified as a scalar in the range `[0,1]`. A value of `1` is opaque and `0` is completely transparent. Values between `0` and `1` are partially transparent.

Boundary line style, specified as one of the options listed in this table.

Line StyleDescriptionResulting Line
`"-"`Solid line

`"--"`Dashed line

`":"`Dotted line

`"-."`Dash-dotted line

`"none"`No lineNo line

Boundary line thickness, specified as a positive number.

Series index, specified as a positive whole number or `"none"`. This property is useful for reassigning the face colors of `ConstantRegion` objects so that they match the colors of other objects.

If the `SeriesIndex` value is a number, MATLAB uses the number to calculate an index for assigning the face color when you call `xregion` and `yregion`. The index refers to the rows of the array stored in the `ColorOrder` property of the axes. Any objects in the axes that have the same `SeriesIndex` number will have the same color.

A `SeriesIndex` value of `"none"` corresponds to a neutral color that does not participate in the indexing scheme.

#### How Manual Color Assignment Overrides `SeriesIndex` Behavior

To manually control fill color, set the `FaceColor` property of the `ConstantRegion` object to a color value, such as a color name or RGB triplet.

When you manually set the fill color of an object, MATLAB does not use automatic color selection for that object, and it allows your color to persist, regardless of the value of the `SeriesIndex` property. The `FaceColorMode` property indicates whether the colors have been set manually (by you) or automatically. A value of `"manual"` indicates manual selection, and a value of `"auto"` indicates automatic selection.

To enable automatic selection, set the `SeriesIndex` property to a positive whole number, and set the `FaceColorMode` property to `"auto"`.

In some cases, MATLAB sets the `SeriesIndex` property to `0`, which also disables automatic color selection.

## Legend

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Legend label, specified as a character vector or string scalar. The legend does not display until you call the `legend` command. If you do not specify the text, then `legend` sets the label using the form `'dataN'`.

Include object in the legend, specified as an `Annotation` object. Set the underlying `IconDisplayStyle` property of the `Annotation` object to one of these values:

• `"on"` — Include the object in the legend (default).

• `"off"` — Do not include the object in the legend.

For example, to exclude the `ConstantRegion` object called `obj` from the legend, set the `IconDisplayStyle` property to `"off"`.

```obj.Annotation.LegendInformation.IconDisplayStyle = "off"; ```

Alternatively, you can control the items in a legend using the `legend` function. Specify the first input argument as a vector of the graphics objects to include. If you do not specify an existing graphics object in the first input argument, then it does not appear in the legend. However, graphics objects added to the axes after the legend is created do appear in the legend. Consider creating the legend after creating all the plots to avoid extra items.

## Interactivity

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State of visibility, specified as `"on"` or `"off"`, or as numeric or logical `1` (`true`) or `0` (`false`). A value of `"on"` is equivalent to `true`, and `"off"` is equivalent to `false`. Thus, you can use the value of this property as a logical value. The value is stored as an on/off logical value of type `matlab.lang.OnOffSwitchState`.

• `"on"` — Display the object.

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

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 `'on'` or `'off'`, or as numeric or logical `1` (`true`) or `0` (`false`). A value of `'on'` is equivalent to true, and `'off'` is equivalent to `false`. Thus, you can use the value of this property as a logical value. The value is stored as an on/off logical value of type `matlab.lang.OnOffSwitchState`.

• `'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 `'on'` or `'off'`, or as numeric or logical `1` (`true`) or `0` (`false`). A value of `'on'` is equivalent to true, and `'off'` is equivalent to `false`. Thus, you can use the value of this property as a logical value. The value is stored as an on/off logical value of type `matlab.lang.OnOffSwitchState`.

• `'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'`.

## Callbacks

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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 — Access properties of the clicked object from within the callback function.

• Event data — Empty argument. 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 Create Callbacks for Graphics Objects.

Note

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

Object creation function, specified as one of these values:

• Function handle.

• Cell array in which the first element is a function handle. Subsequent elements in the cell array are the arguments to pass to the callback function.

• Character vector containing a valid MATLAB expression (not recommended). MATLAB evaluates this expression in the base workspace.

For more information about specifying a callback as a function handle, cell array, or character vector, see Create Callbacks for Graphics Objects.

This property specifies a callback function to execute when MATLAB creates the object. MATLAB initializes all property values before executing the `CreateFcn` callback. If you do not specify the `CreateFcn` property, then MATLAB executes a default creation function.

Setting the `CreateFcn` property on an existing component has no effect.

If you specify this property as a function handle or cell array, you can access the object that is being created using the first argument of the callback function. Otherwise, use the `gcbo` function to access the object.

Object deletion function, specified as one of these values:

• Function handle.

• Cell array in which the first element is a function handle. Subsequent elements in the cell array are the arguments to pass to the callback function.

• Character vector containing a valid MATLAB expression (not recommended). MATLAB evaluates this expression in the base workspace.

For more information about specifying a callback as a function handle, cell array, or character vector, see Create Callbacks for Graphics Objects.

This property specifies a callback function to execute when MATLAB deletes the object. MATLAB executes the `DeleteFcn` callback before destroying the properties of the object. If you do not specify the `DeleteFcn` property, then MATLAB executes a default deletion function.

If you specify this property as a function handle or cell array, you can access the object that is being deleted using the first argument of the callback function. Otherwise, use the `gcbo` function to access the object.

## Callback Execution Control

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Callback interruption, specified as `'on'` or `'off'`, or as numeric or logical `1` (`true`) or `0` (`false`). A value of `'on'` is equivalent to `true`, and `'off'` is equivalent to `false`. Thus, you can use the value of this property as a logical value. The value is stored as an on/off logical value of type `matlab.lang.OnOffSwitchState`.

This 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.

MATLAB determines callback interruption behavior whenever it executes a command that processes the callback queue. These commands include `drawnow`, `figure`, `uifigure`, `getframe`, `waitfor`, and `pause`.

If the running callback does not contain one of these commands, then no interruption occurs. MATLAB first finishes executing the running callback, and later executes the interrupting callback.

If the running callback does contain one of these commands, then the `Interruptible` property of the object that owns the running callback determines if the interruption occurs:

• If the value of `Interruptible` is `'off'`, then no interruption occurs. Instead, the `BusyAction` property of the object that owns the interrupting callback determines if the interrupting callback is discarded or added to the callback queue.

• If the value of `Interruptible` is `'on'`, then the interruption occurs. The next time MATLAB processes the callback queue, it stops the execution of the running callback and executes the interrupting callback. After the interrupting callback completes, MATLAB then resumes executing the running callback.

Note

Callback interruption and execution behave differently in these situations:

• If the interrupting callback is a `DeleteFcn`, `CloseRequestFcn`, or `SizeChangedFcn` callback, then the interruption occurs regardless of the `Interruptible` property value.

• If the running callback is currently executing the `waitfor` function, then the interruption occurs regardless of the `Interruptible` property value.

• If the interrupting callback is owned by a `Timer` object, then the callback executes according to schedule regardless of the `Interruptible` property value.

Note

When an interruption occurs, MATLAB does not save the state of properties or the display. For example, the object returned by the `gca` or `gcf` command might change when another callback executes.

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.

The `BusyAction` property determines callback queuing behavior only when both of these conditions are met:

Under these conditions, the `BusyAction` property of the object that owns the interrupting callback determines how MATLAB handles the interrupting callback. These are possible values of the `BusyAction` property:

• `'queue'` — Puts the interrupting callback in a queue to be processed after the running callback finishes execution.

• `'cancel'` — Does not execute the interrupting callback.

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

• `'visible'` — Capture mouse clicks when visible. The `Visible` property must be set to `'on'` and you must click a part of the `ConstantRegion` 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 `ConstantRegion` object responds to the click or if an ancestor does.

• `'all'` — Capture mouse clicks regardless of visibility. The `Visible` property can be set to `'on'` or `'off'` and you can click a part of the `ConstantRegion` object that has no color. The `HitTest` property determines if the `ConstantRegion` object responds to the click or if an ancestor does.

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

Response to captured mouse clicks, specified as `'on'` or `'off'`, or as numeric or logical `1` (`true`) or `0` (`false`). A value of `'on'` is equivalent to true, and `'off'` is equivalent to `false`. Thus, you can use the value of this property as a logical value. The value is stored as an on/off logical value of type `matlab.lang.OnOffSwitchState`.

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

• `'off'` — Trigger the callbacks for the nearest ancestor of the `ConstantRegion` object that has one of these:

• `HitTest` property set to `'on'`

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

Note

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

Deletion status, returned as an on/off logical value of type `matlab.lang.OnOffSwitchState`.

MATLAB sets the `BeingDeleted` property to `'on'` when the `DeleteFcn` callback begins execution. The `BeingDeleted` property remains set to `'on'` until the component 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.

## Parent/Child

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Parent, specified as an `Axes` object.

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 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 permits 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. Examples of such functions include the `get`, `findobj`, `gca`, `gcf`, `gco`, `newplot`, `cla`, `clf`, and `close` functions.

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

## Identifiers

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Type of graphics object, returned as `'constantregion'`. Use this property to find all objects of a given type within a plotting hierarchy, for example, searching for the type using `findobj`.

Object identifier, specified as a character vector or string scalar. You can specify a unique `Tag` value to serve as an identifier for an object. When you need access to the object elsewhere in your code, you can use the `findobj` function to search for the object based on the `Tag` value.

User data, specified as any MATLAB array. For example, you can specify a scalar, vector, matrix, cell array, character array, table, or structure. Use this property to store arbitrary data on an object.

If you are working in App Designer, create public or private properties in the app to share data instead of using the `UserData` property. For more information, see Share Data Within App Designer Apps.

## Version History

Introduced in R2023a

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