AirspeedIndicator Properties

Control airspeed indicator appearance and behavior

Airspeed indicators are components that represent an airspeed indicator. Properties control the appearance and behavior of an airspeed indicator. Use dot notation to refer to a particular object and property:

f = uifigure;
airspeed = uiaeroairspeed(f);
airspeed.Airspeed = 100;

By default, minor ticks represent 10-knot increments and major ticks represent 40-knot increments. The parameters Minimum and Maximum determine the minimum and maximum values on the gauge. The number and distribution of ticks is fixed, which means that the first and last tick display the minimum and maximum values. The ticks in between distribute evenly between the minimum and maximum values. For major ticks, the distribution of ticks is (Maximum-Minimum)/9. For minor ticks, the distribution of ticks is (Maximum-Minimum)/36.

The airspeed indicator has scale color bars that allow for overlapping for the first bar, displayed at a different radius. This different radius lets the block represent maximum speed with flap extended (V_FE) and stall speed with flap extended (V_SO) accurately for aircraft airspeed and stall speed.

Airspeed Indicator

Airspeed — Airspeed

0 (default) | finite, real, and scalar numeric

Airspeed value, specified as a finite, real, and scalar numeric, in knots. The airspeed value determines the airspeed of the aircraft.

• If the value is less than the minimum Limits property value, then the needle points to a location immediately before the beginning of the scale.

• If the value is more than the maximum Limits property value, then the needle points to a location immediately after the end of the scale.

Example: 100

Limits — Minimum and maximum airspeed indicator scale values

[40 400] (default) | two-element finite and real numeric array

Minimum and maximum gauge scale values, specified as a two-element numeric array. The first value in the array must be less than the second value, in knots.

If you change Limits such that the Value property is less than the new lower limit, or more than the new upper limit, then the gauge needle points to a location off the scale.

For example, suppose Limits is [0 100] and the Value property is 20. If the Limits changes to [50 100], then the needle points to a location off the scale, slightly less than 50.

ScaleColors — Scale colors

[ ] (default) | 1-by-n string array | 1-by-n cell array | n-by-3 array of RGB triplets | hexadecimal color code | ...

Scale colors, specified as one of the following arrays:

• A 1-by-n string array of color options, such as ["blue" "green" "red"].

• An n-by-3 array of RGB triplets, such as [0 0 1;1 1 0].

• A 1-by-n cell array containing RGB triplets, hexadecimal color codes, or named color options. For example, {'#EDB120','#7E2F8E','#77AC30'}.

RGB triplets and hexadecimal color codes are useful for specifying custom colors.

• 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 character vector or a string scalar 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. Thus, 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 Name	Short Name	RGB Triplet	Hexadecimal Color Code	Appearance
"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"

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

RGB Triplet	Hexadecimal Color Code	Appearance
[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"

Each color of the ScaleColors array corresponds to a colored section of the gauge. Set the ScaleColorLimits property to map the colors to specific sections of the gauge.

If you do not set the ScaleColorLimits property, MATLAB distributes the colors equally over the range of the gauge.

ScaleColorLimits — Scale color limits

[ ] (default) | n-by-2 array

Scale color limits, specified as an n-by-2 array of numeric values. For every row in the array, the first element must be less than the second element. The first ScaleColorLimits value can overlap (see Display Flight Trajectory Data Using Flight Instruments and Flight Animation).

When applying colors to the gauge, MATLAB applies the colors starting with the first color in the ScaleColors array. Therefore, if two rows in ScaleColorLimits array overlap, then the color applied later takes precedence.

The gauge does not display any portion of the ScaleColorLimits that falls outside of the Limits property.

If the ScaleColors and ScaleColorLimits property values are different sizes, then the gauge shows only the colors that have matching limits. For example, if the ScaleColors array has three colors, but the ScaleColorLimits has only two rows, then the gauge displays the first two color/limit pairs only.

Value — Airspeed

0 (default) | finite, real, and scalar numeric

Airspeed value, specified as a finite, real, and scalar numeric. The airspeed value determines the airspeed of the aircraft.

• If the value is less than the minimum Limits property value, then the needle points to a location immediately before the beginning of the scale.

• If the value is more than the maximum Limits property value, then the needle points to a location immediately after the end of the scale.

Example: 100

Interactivity

Visible — Visibility of airspeed indicator

'on' (default) | on/off logical value

Visibility of the airspeed indicator, 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. The Visible property determines whether the airspeed indicator is displayed on the screen. If the Visible property is set to 'off', then the entire airspeed indicator is hidden, but you can still specify and access its properties.

ContextMenu — Context menu

empty GraphicsPlaceholder array (default) | ContextMenu object

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

Enable — Operational state of airspeed indicator

'on' (default) | on/off logical value

Operational state of airspeed indicator, 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.

• If you set this property to 'on', then the appearance of the indicator indicates that the indicator is operational.

• If you set this property to 'off', then the appearance of the indicator appears dimmed, indicating that the indicator is not operational.

Position

Position — Location and size of airspeed indicator

[100 100 120 120] (default) | [left bottom width height]

Location and size of the airspeed indicator relative to the parent container, specified as the vector, [left bottom width height]. This table describes each element in the vector.

Element	Description
left	Distance from the inner left edge of the parent container to the outer left edge of an imaginary box surrounding the airspeed indicator
bottom	Distance from the inner bottom edge of the parent container to the outer bottom edge of an imaginary box surrounding the airspeed indicator
width	Distance between the right and left outer edges of the airspeed indicator
height	Distance between the top and bottom outer edges of the airspeed indicator

All measurements are in pixel units.

The Position values are relative to the drawable area of the parent container. The drawable area is the area inside the borders of the container and does not include the area occupied by decorations such as a menu bar or title.

Example: [200 120 120 120]

InnerPosition — Inner location and size of airspeed indicator

[100 100 120 120] (default) | [left bottom width height]

Inner location and size of the airspeed indicator, specified as [left bottom width height]. Position values are relative to the parent container. All measurements are in pixel units. This property value is identical to the Position property.

OuterPosition — Outer location and size of airspeed indicator

[100 100 120 120]] (default) | [left bottom width height]

This property is read-only.

Outer location and size of the airspeed indicator returned as [left bottom width height]. Position values are relative to the parent container. All measurements are in pixel units. This property value is identical to the Position property.

Layout — Layout options

empty LayoutOptions array (default) | GridLayoutOptions object

Layout options, specified as a GridLayoutOptions object. This property specifies options for components that are children of grid layout containers. If the component is not a child of a grid layout container (for example, it is a child of a figure or panel), then this property is empty and has no effect. However, if the component is a child of a grid layout container, you can place the component in the desired row and column of the grid by setting the Row and Column properties on the GridLayoutOptions object.

For example, this code places an airspeed indicator in the third row and second column of its parent grid.

g = uigridlayout([4 3]);
gauge = uiaeroairspeed(g);
gauge.Layout.Row = 3;
gauge.Layout.Column = 2;

To make the airspeed indicator span multiple rows or columns, specify the Row or Column property as a two-element vector. For example, this airspeed indicator spans columns 2 through 3:

gauge.Layout.Column = [2 3];

Callbacks

CreateFcn — Creation function

'' (default) | function handle | cell array | character vector

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 Callbacks in App Designer.

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.

DeleteFcn — Deletion function

'' (default) | function handle | cell array | character vector

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 Callbacks in App Designer.

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

Interruptible — Callback interruption

'on' (default) | on/off logical value

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.

BusyAction — Callback queuing

'queue' (default) | 'cancel'

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:

• The running callback contains a command that processes the callback queue, such as drawnow, figure, uifigure, getframe, waitfor, or pause.

• The value of the Interruptible property of the object that owns the running callback is 'off'.

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.

BeingDeleted — Deletion status

on/off logical value

This property is read-only.

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

HandleVisibility — Visibility of object handle

'on' (default) | 'callback' | 'off'

Visibility of the object handle, specified as 'on', 'callback', or 'off'.

This property controls the visibility of the object in its parent's list of children. When an object is not visible in its parent's list of children, it is not returned by functions that obtain objects by searching the object hierarchy or querying properties. These functions include get, findobj, clf, and close. Objects are valid even if they are not visible. If you can access an object, you can set and get its properties, and pass it to any function that operates on objects.

HandleVisibility Value	Description
'on'	The object is always visible.
'callback'	The object 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.
'off'	The object 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 object during the execution of that function.

Parent — Parent container

Figure object (default) | Panel object | Tab object | ButtonGroup object | GridLayout object

Parent container, specified as a Figure object created using the uifigure function, or one of its child containers: Tab, Panel, ButtonGroup, or GridLayout. If no container is specified, MATLAB calls the uifigure function to create a new Figure object that serves as the parent container.

Identifiers

Tag — Object identifier

'' (default) | character vector | string scalar

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.

Type — Type of graphics object

'uiaeroairspeed'

This property is read-only.

Type of graphics object, returned as 'uiaeroairspeed'.

UserData — User data

[] (default) | array

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 R2018b