Page 83 - Basics of MATLAB and Beyond

Beyond the Basics

Prelude

This part of the book assumes that you already have some competency
with matlab. You may have been using it for a while and you find you
want to do more with it. Perhaps you have seen what other people do
and are wondering how it is done. Well, read on.
This part of the book follows an introductory course in matlab
(Part I) that covered the basics: matrices, typing shortcuts, basic graph-
ics, basic algebra and data analysis, basics of m-files and data files, and
a few simple applications, such as curve fitting, FFTs, and sound. Basic
handle graphics were introduced using set and get.
We begin by looking at sparse matrices and strings, go on to deal
with some of the data types that are new to matlab version 5: cell
arrays, multidimensional arrays and structures, then deal with a variety
of topics that you will probably have to deal with at some stage if you are
a frequent user of matlab. The book can be worked through from start
to finish, but if you are not interested in a particular topic, you can skip
over it without affecting your understanding of later topics. Exercises
are given throughout the book, and answers to most of them are given
at the end. We start by introducing some new variable types that go
beyond the functionality of a rectangular matrix.

25 Sparse Arrays

In some applications, matrices have only a few non-zero elements. Such
matrices might arise, for example, when analysing communication net-
works or when performing finite element modelling. matlab provides
sparse arrays for dealing with such cases. Sparse arrays take up much
less storage space and calculation time than full arrays.

c 2000 by CRC Press LLC