What Is the Wavelet Toolbox? :: Wavelets: A New Tool for Signal Analysis (Wavelet Toolbox)

Wavelet Toolbox

What Is the Wavelet Toolbox?

Everywhere around us are signals that can be analyzed. For example, there are seismic tremors, human speech, engine vibrations, medical images, financial data, music, and many other types of signals. Wavelet analysis is a new and promising set of tools and techniques for analyzing these signals.

The Wavelet Toolbox is a collection of functions built on the MATLAB^® Technical Computing Environment. It provides tools for the analysis and synthesis of signals and images, and tools for statistical applications, using wavelets and wavelet packets within the framework of MATLAB.

The MathWorks provides several products that are relevant to the kinds of tasks you can perform with the Wavelet Toolbox. For more information about any of these products, see the products section of The MathWorks Web site, at http://www.mathworks.com.

The Wavelets Toolbox provides two categories of tools:

Command line functions
Graphical interactive tools

The first category of tools is made up of functions that you can call directly from the command line or from your own applications. Most of these functions are M-files, series of statements that implement specialized wavelet analysis or synthesis algorithms. You can view the code for these functions using the following statement:

```
type function_name
```

You can view the header of the function, the help part, using the statement

```
help function_name
```

A summary list of the Wavelet Toolbox functions is available to you by typing

```
help wavelet
```

You can change the way any toolbox function works by copying and renaming the M-file, then modifying your copy. You can also extend the toolbox by adding your own M-files.

The second category of tools is a collection of graphical interface tools that afford access to extensive functionality. Access these tools by typing

```
wavemenu
```

from the command line.

Note The examples of this guide are generated using the Wavelet Toolbox with the DWT extension mode set to 'zpd' (for zero padding), except when it is explicitly mentioned. So if you want to obtain exactly the same numerical results, type dwtmode('zpd'), before to execute the example code.

In most of the command line examples, figures are displayed. To clarify the presentation, the plotting commands are partially or completely omitted. To reproduce the displayed figures exactly, you would need to insert some graphical commands in the example code.

Wavelets: A New Tool for Signal Analysis Background Reading