Getting Started

Graphics Objects

Graphics objects are the basic elements used to display graphics and user interface elements. This table lists the graphics objects.

Object	Description
Root	Top of the hierarchy corresponding to the computer screen
Figure	Window used to display graphics and user interfaces
Axes	Axes for displaying graphs in a figure
Uicontrol	User interface control that executes a function in response to user interaction
Uimenu	User-defined figure window menu
Uicontextmenu	Pop-up menu invoked by right clicking on a graphics object
Image	Two-dimensional pixel-based picture
Light	Light sources that affect the coloring of patch and surface objects
Line	Line used by functions such as plot, plot3, semilogx
Patch	Filled polygon with edges
Rectangle	Two-dimensional shape varying from rectangles to ovals
Surface	Three-dimensional representation of matrix data created by plotting the value of the data as heights above the x-y plane
Text	Character string

Object Hierarchy

The objects are organized in a tree structured hierarchy reflecting their interdependence. For example, line objects require axes objects as a frame of reference. In turn, axes objects exist only within figure objects. This diagram illustrates the tree structure.

Creating Objects

Each object has an associated function that creates the object. These functions have the same name as the objects they create. For example, the text function creates text objects, the figure function creates figure objects, and so on. MATLAB high-level graphics functions (like plot and surf) call the appropriate low-level function to draw their respective graphics. For more information about an object and a description of its properties, see the reference page for the object's creation function. Object creation functions have the same name as the object. For example, the object creation function for axes objects is called axes.

Commands for Working with Objects

This table lists commands commonly used when working with objects.

Function	Purpose
copyobj	Copy graphics object
delete	Delete an object
findobj	Find the handle 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 value of an objects properties
set	Set the value of an objects properties

Handle Graphics

Setting Object Properties