MATLAB Primer - Introduction to Digital Signal Processing and Filter Design - page 405

Plot of the function f(x)

11

10

9

8

f(x) = 2x + 0.5/x 2 + 0.1x + 0.05

7

6

5

4

3

2

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Value of x

0 . 5 )/(x 2

Figure 9.3 Plot of ( 2 x + + 0 . 1 x + 0 . 05 ) .

9.2 SIGNAL PROCESSING TOOLBOX

The Signal Processing Toolbox is a collection of about 160 functions that are
extensively used for the analysis, design, and realization of discrete-time sys-
tems and tasks or operations such as modeling, detection, filtering, prediction,
and spectral analysis in digital signal processing. They run under MATLAB,
which has about 330 functions and operations. By typing help function in
the command window, where function is the name of these functions, detailed
information about them is displayed. By typing help signal ,wegetacom-
plete list of all the functions in the Signal Processing Toolbox, when this has
been installed as a subdirectory of the MATLAB directory. If we know the name
of the function that does the numerical processing but not the syntax and other
details, we can type help function . But when we have to carry out numerical
processing but don't know the name of the MATLAB function, we may have to
go through the list of all MATLAB functions and choose the appropriate one for
the purpose. The list of all MATLAB functions in the Signal Processing Toolbox
is given in Section 9.2.1, and students are encouraged to use the help utility and
become familiar with as many of the functions as possible. That should improve
their efficiency in calling up the appropriate function immediately when the need
arises while they write and edit the script. Note that we can use any of the thou-
sands of functions found in all other toolboxes and in the simulation software
called Simulink that runs under MATLAB, which makes this software extremely
powerful and versatile.