Introduction to the MATLAB Environment - Digital Signal Processing: Fundamentals and Applications - page 774

% sub ¼ x1-x2
sum ¼ x1+x2; % Add two numbers
sub ¼ x1-x2; % Subtract x2 from x1
To use the MATLAB function, go to the folder that contains sumsub.m. At the MATLAB prompt,
try the following:
»

help sumsub % Display usage information on MATLAB prompt
sumsub: Function to add and subtract two numbers
usage:
[sum, sub] sumsub(x1,x2)

¼

x1 the first number

¼

x2 the second number

¼

sum x1+x2;

sub ¼ x1-x2
Run the function as follows:

¼

» [x1, x2] ¼ sumsub(3, 4-3i); % Call function sumsub

» x1 % Display the result of sum

x1 ¼
7.0000 - 3.0000i

» x2 % Display the result of subtraction

x2 ¼
-1.0000 + 3.0000i
MATLAB functions can also be used inside an m-file. More MATLAB exercises for introduction to
DSP can be explored in McClellan, Schafer, and Yoder (1998) and Stearns (2003).