Graphics Programs Reference

In-Depth Information

You can design and apply filters to data in a similar way.

23 Handle Graphics

So far in this topic, we have only used matlab's high-level plotting

function (
plot
,
surf
, etc.). High-level plotting functions produce simple

graphs and automate the many mundane decisions you might make in

producing a plot, such as the position of the plot, the colour of the axes,

the font size, the line thickness, and so on. matlab's system of
Handle

Graphics
allows you to control a great many of these “mundane” aspects

of plotting, to produce plots that are optimised for communicating the

data at hand. The idea behind Handle Graphics is that every object in

the figure window (axes, lines, text, surfaces, etc.) has a set of properties.

These properties can be examined using the
get
command and set to new

values using the
set
command. Every object in the figure window also

has a unique identifier (a number) called a
handle
. The object's handle

tells
get
and
set
what object you are interested in. As an introductory

example, consider the plot shown on page 58 of the frequency modulated

sinusoid: