Graphics Objects :: Graphics (Getting Started)

Getting Started

Graphics Objects

Graphics objects are the basic elements used to display graphs and user interface components. These objects are organized into a hierarchy, as shown by the following diagram.

Key Graphics Objects

When you call a function to create a graph, MATLAB creates a hierarchy of graphics objects. For example, calling the plot function creates the following graphics objects:

Lineseries plot objects -- Represent the data passed to the plot function
Axes -- Provide a frame of reference and scaling for the plotted lineseries
Text -- Label the axes tick marks and are used for titles and annotations
Figures -- Are the windows that contain axes toolbars, menus, etc.

Different types of graphs use different objects to represent data: however, all data objects are contained in axes and all objects (except root) are contained in figures.

The root is an abstract object that primarily stores information about your computer or MATLAB state. You cannot create an instance of the root object.

For More Information See Handle Graphics Objects in the MATLAB documentation for information on graphics objects.

User interface objects are used to create graphical user interfaces (GUIs). These objects include components like push buttons, editable text boxes, and list boxes.

For More Information See Creating Graphical User Interfaces in the MATLAB documentation for more information on user interface objects.

Creating Objects

Plotting functions (like plot and surf) call the appropriate low-level function to draw their respective graph. For information about an object's properties, see the Handle Graphics Property Browser in the MATLAB online documentation.

Commands for Working with Objects

This table lists commands commonly used when working with objects.

Function
Purpose

allchild
Find all children of specified objects

ancestor
Find ancestor of graphics object

copyobj
Copy graphics object

delete
Delete an object

findall
Find all graphics objects (including hidden handles)

findobj
Find the handles of objects having specified property values

gca
Return the handle of the current axes

gcf
Return the handle of the current figure

gco
Return the handle of the current object

get
Query the values of an object's properties

ishandle
True if value is valid object handle

set
Set the values of an object's properties

Function	Purpose
`allchild`	Find all children of specified objects
`ancestor`	Find ancestor of graphics object
`copyobj`	Copy graphics object
`delete`	Delete an object
`findall`	Find all graphics objects (including hidden handles)
`findobj`	Find the handles of objects having specified property values
`gca`	Return the handle of the current axes
`gcf`	Return the handle of the current figure
`gco`	Return the handle of the current object
`get`	Query the values of an object's properties
`ishandle`	True if value is valid object handle
`set`	Set the values of an object's properties

Handle Graphics Setting Object Properties