Root Properties (MATLAB Functions)

MATLAB Function Reference

Root Properties
Modifying Properties

You can set and query graphics object properties in two ways:

The Property Editor is an interactive tool that enables you to see and change object property values.
The set and get commands enable you to set and query the values of properties.

To change the default values of properties, see Setting Default Property Values.

Root Properties

This section lists property names along with the type of values each accepts. Curly braces { } enclose default values.

BusyAction cancel | {queue}

Not used by the root object.

ButtonDownFcn string

Not used by the root object.

CallbackObject handle (read only)

Handle of current callback's object. This property contains the handle of the object whose callback routine is currently executing. If no callback routines are executing, this property contains the empty matrix [ ]. See also the gco command.

CaptureMatrix (obsolete)

This property has been superseded by the getframe command.

CaptureRect (obsolete)

This property has been superseded by the getframe command.

Children vector of handles

Handles of child objects. A vector containing the handles of all nonhidden figure objects (see HandleVisibility for more information). You can change the order of the handles and thereby change the stacking order of the figures on the display.

Clipping {on} | off

Clipping has no effect on the root object.

CommandWindowSize [columns rows]

Current size of command window. This property contains the size of the MATLAB command window in a two-element vector. The first element is the number of columns wide and the second element is the number of rows tall.

CreateFcn

The root does not use this property.

CurrentFigure figure handle

Handle of the current figure window, which is the one most recently created, clicked in, or made current with the statement

```
figure(h)
```

which restacks the figure to the top of the screen, or

```
set(0,'CurrentFigure',h)
```

which does not restack the figures. In these statements, h is the handle of an existing figure. If there are no figure objects,

```
get(0,'CurrentFigure')
```

returns the empty matrix. Note, however, that gcf always returns a figure handle, and creates one if there are no figure objects.

DeleteFcn string

This property is not used, because you cannot delete the root object.

Diary on | {off}

Diary file mode. When this property is on, MATLAB maintains a file (whose name is specified by the DiaryFile property) that saves a copy of all keyboard input and most of the resulting output. See also the diary command.

DiaryFile string

Diary filename. The name of the diary file. The default name is diary.

Echo on | {off}

Script echoing mode. When Echo is on, MATLAB displays each line of a script file as it executes. See also the echo command.

ErrorMessage string

Text of last error message. This property contains the last error message issued by MATLAB.

FixedWidthFontName font name

Fixed-width font to use for axes, text, and uicontrols whose FontName is set to FixedWidth. MATLAB uses the font name specified for this property as the value for axes, text, and uicontrol FontName properties when their FontName property is set to FixedWidth. Specifying the font name with this property eliminates the need to hardcode font names in MATLAB applications and thereby enables these applications to run without modification in locales where non-ASCII character sets are required. In these cases, MATLAB attempts to set the value of FixedWidthFontName to the correct value for a given locale.

MATLAB application developers should not change this property, but should create axes, text, and uicontrols with FontName properties set to FixedWidth when they want to use a fixed-width font for these objects.

MATLAB end users can set this property if they do not want to use the preselected value. In locales where Latin-based characters are used, Courier is the default.

Format

short | {shortE} | long | longE | bank |
                             hex | + | rat

Output format mode. This property sets the format used to display numbers. See also the format command.

short -- Fixed-point format with 5 digits
shortE -- Floating-point format with 5 digits
shortG -- Fixed- or floating-point format displaying as many significant figures as possible with 5 digits
long -- Scaled fixed-point format with 15 digits
longE -- Floating-point format with 15 digits
longG -- Fixed- or floating-point format displaying as many significant figures as possible with 15 digits
bank -- Fixed-format of dollars and cents
hex -- Hexadecimal format
+ -- Displays + and - symbols
rat -- Approximation by ratio of small integers

FormatSpacing compact | {loose}

Output format spacing (see also format command).

compact -- Suppress extra line feeds for more compact display.
loose -- Display extra line feeds for a more readable display.

HandleVisibility {on} | callback | off

This property is not useful on the root object.

HitTest {on} | off

This property is not useful on the root object.

Interruptible {on} | off

This property is not useful on the root object.

Language string

System environment setting.

MonitorPosition [x y width height;x y width height]

Width and height of primary and secondary monitors, in pixels. This property contains the width and height of each monitor connnected to your computer. The x and y values for the primary monitor are 0, 0 and the width and height of the monitor are specified in pixels.

The secondary monitor position is specified as

x = primary monitor width + 1
y = primary monitor height + 1

Querying the value of the figure MonitorPosition on a multiheaded system returns the position for each monitor on a separate line.

v = get(0,'MonitorPosition')
v = 
       x y width height % Primary monitor
       x y width height % Secondary monitor

Note that MATLAB sets the value of the ScreenSize property to the combined size of the monitors.

Parent handle

Handle of parent object. This property always contains the empty matrix, because the root object has no parent.

PointerLocation [x,y]

Current location of pointer. A vector containing the x- and y-coordinates of the pointer position, measured from the lower left corner of the screen. You can move the pointer by changing the values of this property. The Units property determines the units of this measurement.

This property always contains the current pointer location, even if the pointer is not in a MATLAB window. A callback routine querying the PointerLocation can get a value different from the location of the pointer when the callback was triggered. This difference results from delays in callback execution caused by competition for system resources.

On Macintosh platforms, you cannot change the pointer location using the set command.

PointerWindowhandle (read only)

Handle of window containing the pointer. MATLAB sets this property to the handle of the figure window containing the pointer. If the pointer is not in a MATLAB window, the value of this property is 0. A callback routine querying the PointerWindow can get the wrong window handle if you move the pointer to another window before the callback executes. This error results from delays in callback execution caused by competition for system resources.

RecursionLimit integer

Number of nested M-file calls. This property sets a limit to the number of nested calls to M-files MATLAB will make before stopping (or potentially running out of memory). By default the value is set to a large value. Setting this property to a smaller value (something like 150, for example) should prevent MATLAB from running out of memory and will instead cause MATLAB to issue an error when the limit is reached.

ScreenDepth bits per pixel

Screen depth. The depth of the display bitmap (i.e., the number of bits per pixel). The maximum number of simultaneously displayed colors on the current graphics device is 2 raised to this power.

ScreenDepth supersedes the BlackAndWhite property. To override automatic hardware checking, set this property to 1. This value causes MATLAB to assume the display is monochrome. This is useful if MATLAB is running on color hardware but is being displayed on a monochrome terminal. Such a situation can cause MATLAB to determine erroneously that the display is color.

ScreenPixelsPerInch Display resolution

DPI setting for your display. This property contains the setting of your display resolution specified in your system preferences.

ScreenSize four-element rectangle vector (read only)

Screen size. A four-element vector,

```
[left,bottom,width,height]
```

that defines the display size. left and bottom are 0 for all Units except pixels, in which case left and bottom are 1. width and height are the screen dimensions in units specified by the Units property.

Selected on | off

This property has no effect on the root level.

SelectionHighlight {on} | off

This property has no effect on the root level.

ShowHiddenHandles on | {off}

Show or hide handles marked as hidden. When set to on, this property disables handle hiding and exposes all object handles regardless of the setting of an object's HandleVisibility property. When set to off, all objects so marked remain hidden within the graphics hierarchy.

Tag string

User-specified object label. The Tag property provides a means to identify graphics objects with a user-specified label. While it is not necessary to identify the root object with a tag (since its handle is always 0), you can use this property to store any string value that you can later retrieve using set.

Type string (read only)

Class of graphics object. For the root object, Type is always 'root'.

UIContextMenu handle

This property has no effect on the root level.

Units

{pixels} | normalized | inches | centimeters
                     | points | characters

Unit of measurement. This property specifies the units MATLAB uses to interpret size and location data. All units are measured from the lower left corner of the screen. Normalized units map the lower left corner of the screen to (0,0) and the upper right corner to (1.0,1.0). inches, centimeters, and points are absolute units (one point equals 1/72 of an inch). Characters are units defined by characters from the default system font; the width of one unit is the width of the letter x, the height of one character is the distance between the baselines of two lines of text.

This property affects the PointerLocation and ScreenSize properties. If you change the value of Units, it is good practice to return it to its default value after completing your operation, so as not to affect other functions that assume Units is set to the default value.

UserData matrix

User-specified data. This property can be any data you want to associate with the root object. MATLAB does not use this property, but you can access it using the set and get functions.

Visible {on} | off

Object visibility. This property has no effect on the root object.

root object roots