Introduction to the MATLAB Environment - Digital Signal Processing: Fundamentals and Applications - page 773

Test plots of sinusoids

1

0.8

0.6

0.4

0.2

0

-0.2

-0.4

-0.6

-0.8

-1

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Time (sec.)

FIGURE A.2

Illustration of MATLAB script file test.m.

xlabel( ' Time (sec.) ' ); hold on

plot(t,y, -. );

' '

A.5 MATLAB FUNCTIONS
A MATLAB function is often used to replace the repetitive portions of MATLAB code. It is
created using a MATLAB script file. However, the code begins with the keyword function,
followed by the function declaration, comments for the help system, and program code.
A function sumsub.m that computes the addition and subtraction of two numbers is listed here
for illustration.
sumsub.m

function [sum, sub] ¼ sumsub(x1,x2)
%sumsub: Function to add and subtract two numbers
% Usage:
% [sum, sub] ¼ sumsub(x1,x2)
%x1 ¼ the first number
%x2 ¼ the second number
% sum ¼ x1+x2;