# root object

## Purpose

Root object properties.

## Description

The root is a handle graphics object that corresponds to the computer screen. There is only one root object and it has no parent. The children of the root object are figure windows.

The root object exists when you start MATLAB; you never have to create it. Use the `set` function to alter the root's properties, listed under "Object Properties" below. Use `get` to query the root's properties.

## Object Properties

This section lists property names along with the type of values each accepts.

`BlackAndWhite`
  Automatic hardware checking flag.

  `on` Assume the display is monochrome. This is useful if MATLAB is running on color hardware, but is displaying on a monochrome terminal. Prevents MATLAB from determining erroneously that the display is color.
  `off` (Default.) Differentiate between color and monochrome.

`ButtonDownFcn`
  Callback string.

  Any legal MATLAB expression, including the name of an M-file or function. When you select the object, the string is passed to the `eval` function to execute the `Callback`. Initially the empty matrix.

`CaptureMatrix`
  Matrix of screen data.

  A read-only matrix that contains the image data of the region enclosed by the `CaptureRect` rectangle. Use the `get` function to obtain this matrix. Use `image` to display the captured matrix.

`CaptureRect`
  Size and position of rectangle to capture.

  A four-element vector, `[left,bottom,width,height]`, that defines the region captured by `CaptureMatrix`. `left` and `bottom` define the location of the lower-left corner of the rectangle and `width` and `height` define the dimensions of the rectangle. The `Units` property determines what units are used to specify these dimensions. Initial value is `[0 0 0 0]`.

`Children`
  Handles of child objects.

  A read-only vector containing the handles of all figure objects.

`Clipping`
  Data clipping.

  `on` (Default.) No effect for root objects.
  `off` No effect for root objects.

`CurrentFigure`
  Current figure window.

  The handle of the current figure.

`Diary`
  Diary file mode (see also `diary` command).

  `on` MATLAB maintains a file (with name `DiaryFile`) that saves a copy of all keyboard input and most of the resulting output.
  `off` (Default.) MATLAB does not save input and output to a file.

`DiaryFile`
  Diary file name.

  A string containing the name of the diary file. The default name is `diary`.

`Echo`
  Script echoing mode (see also `echo` command).

  `on` MATLAB displays each line of a script file as it executes.
  `off` (Default.) MATLAB does not echo during script execution.

`Format`
  Output format mode (see also `format` command).

  `short` (Default.) Fixed-point format with 5 digits.
  `shortE` Floating-point format with 5 digits.
  `long` Scaled fixed-point format with 15 digits.
  `longE` Floating-point format with 15 digits.
  `bank` Fixed-format of dollars and cents.
  `hex` Hexadecimal format.
  `+` Displays + and - symbols.

`FormatSpacing`
  Output format spacing (see also `format` command).

  `compact` Suppress extra line feeds for more compact display.
  `loose` (Default.) Display extra line feeds for looser display.

`Interruptible`
  Callback interruptibility.

  `yes` The callback specified by `ButtonDownFcn` is interruptible by other callbacks.
  `no` (Default.) The `ButtonDownFcn` callback is not interruptible.

`Parent`
  Handle of parent object.

  A read-only property that always contains the empty matrix, as the root object has no parent.

`PointerLocation`
  Current location of pointer.

  A read-only vector containing the x- and y-coordinates of the pointer position, measured from the lower-left corner of the screen. The `Units` property determines the units of this measurement.
  This property always contains the instantaneous pointer location, even if the pointer is not in a MATLAB window. This location may change by the time the value is returned.

`PointerWindow`
  Handle of window containing the pointer.

  A read-only property containing the handle of the figure window that contains the pointer. If the pointer is not in a MATLAB window, the value of the property is 0.

`ScreenDepth`
  Screen depth.

  An integer specifying the screen depth in bits.

`ScreenSize`
  Screen size.

  A four-element read-only vector, `[left,bottom,width,height]`, that defines the display size. `left` and `bottom` are always 0. `width` and `height` are the screen dimensions in units specified by the `Units` property.

`TerminalOneWindow`
  Indicates if there is only one window on your terminal.

  `yes` There is only one window on your terminal.
  `no` Multiple windows.
  If the terminal uses only one window, MATLAB waits for you to press a key before it switches from graph mode back to command mode. This property is only used by the terminal graphics driver.

`TerminalProtocol`
  Terminal type.

  `x` X display server. If you are using X Windows and MATLAB can connect to your X display server, this property is automatically set to `x`.
  `tek401x` Terminals that emulate Tektronix 4010/4014.
  `tek410x` Terminals that emulate Tektronix 4100/4105.
  `none` Not in terminal mode, not connected to an X server.
  Once this property is set, it cannot be changed unless you quit and restart MATLAB.

`Type`
  Type of graphics object.

  A read-only string; always `'root'` for the root object.

`Units`
  Unit of measurement.

  `pixels` (Default.) Screen pixels.
  `normalized` Normalized coordinates, where the lower-left corner of the screen maps to (0,0) and the upper-right corner to (1.0,1.0).
  `inches` Inches.
  `cent` Centimeters.
  `points` Points. Each point is equivalent to 1/72 of an inch.
  This property affects `CaptureRect`, `PointerLocation`, and `ScreenSize`. If you change the value of `Units`, it is good practice to return it to its default value after completing your computation so as not to affect other functions that assume `Units` is set to the default value.

`UserData`
  User-specified data.

  Any matrix you want to associate with the root object. The object does not use this data, but you can retrieve it using the `get` command`.`

`Visible`
  Object visibility.

  `on` (Default.) No effect for root objects.
  `off` No effect for root objects.

## See Also

    diary, echo, figure, format, gcf

(c) Copyright 1994 by The MathWorks, Inc.