## MATLAB BASICS AND A LITTLE BEYOND

## A short introduction to Matlab

The purpose of this web page is to *introduce* Matlab to students of
mathematics. It is not exhaustive, but describes commands and
subroutines that might be commonly used by mathematicians.

This tutorial is intended as a cut and paste
tutorial to Matlab's capabilities. The reader would be served to
have this web page open along with a Matlab window. To execute Matlab
in a Unix environment, at the prompt, type

matlab

and return. If Matlab is successfully executed, a small pop
up window will appear with the Matlab logo. In the Unix window,
an introductory message will stream by and the matlab prompt
>>

will appear. To enter commands in Matlab, simply type them in.
Beware that Matlab is case sensitive.
This tutorial contains Matlab code. Each line of Matlab code starts
with the prompt >>. *When you cut a segment of code from this tutorial,
do not cut the prompt * >> .

# Matlab's advantages

Matlab is an interpreted language for numerical computation. It
allows one to perform numerical calculations, and visualize the results
without the need for complicated and time consuming programming. Matlab
allows its users to accurately solve problems, produce graphics easily
and produce code effeciently.

# Matlab's disadvantages

Because Matlab is an interpreted language, it can be slow, and poor
programming practices can make it unacceptably slow.

# Some features of Matlab

1.1 Inline help

1.2 Web based support and help

1.3 Who, whos and clear

1.4 Recording your Matlab session

2.1 Dense matrices and vectors

2.2 Sparse matrices and vectors

2.3 Range operators

2.4 Grid operators

2.5 Size and shape operators

2.6 Special matrices

3.1 Matrix-vector operations

3.2 Array operations

3.3 Backslash operator

3.4 Complex arithmetic

4.0 Elementary functions

4.1 Linear algebra

4.2 Nonlinear functions

4.3 Ordinary differential equations

4.4 Fourier transformations

5.1 Plotting (x,y) data

5.2 Axis control

5.3 Plotting (x,y,z) data

5.4 Saving postscript graphs

5.5 Movies

6.1 Importing ascii data

6.2 Exporting ascii data

7.1 Some basics

7.2 m-files

7.3 Good practices

8.1 Matrix examples

8.1.1 Largest eigenvalue of a random dispersion matrix

8.1.2

8.2 Partial differential equations

8.2.1 Solve a semi-linear heat equation

8.2.2 Solve the Cahn-Hilliard equation

9.1 Using C++ with Matlab

*David Eyre*

*9/8/1998*