Creating a Function in MATLAB

Functions in MATLAB can be interpreted as programs. The function consists of one or several commands in MATLAB. The MATLAB function is stored in m-files. M-files are text files containing MATLAB commands and stored with the .m extension. Editors to create m-files can be activated using the toolbar. The function has a special syntax on the first line. In general the syntax is:

function [out1, ..., outM] = func_name (in1, ..., inN)

A function does not have to be written with an input or output argument (out1, ..., OutM is the output argument, while in1, ..., inN is the input argument). The functions written above will be stored in a file with the name func_name.m. The function has its own workspace. Information communication between the workspace function and the main workspace is done through input and output variables. It's a good idea to put a few lines of comments at the beginning of a function to explain the usefulness of the program.

The following will be given three simple m-file examples using the input and output arguments. The three files are:

Example 1. Addition of Two Variables (scalar / vector / matrix)

To create a new function in MATLAB, the first step to do is to add New Script. where the procedure for writing the correct addition function is as below,

function f = example1(x, y)

% function to add two variable functions

% and print the results in the command window

f=x + y;

end

After that save it with the file name is example1.m

To call a function that was created before, open the folder location where Example1.m is stored. After that, call it by writing the name of the function in the Command Window as below,

Example 2 Summing three variables (scalar / vector / matrix).

Like example 1, create a new script with the name of the function example2 and save it in the same folder as the function example1. Where the example2 function has three input arguments (x, y, and z) and one output argument (s).

function s=example2(x,y,z)

% Adds three variables

% and save the results

s=x+y+z;

end

Now call the function that has been created as shown in the image below,

Example 3 Calculate the number and multiplication of two variables (scalar / vector / matrix)

Below is an m-file with the name function example3. Two input arguments (x and y) and two output arguments (s and p). M-file to calculate the number and multiplication of two variables then save the results (save with file name A: \ example3.m).

function [s, p] = example3 (x, y)

% calculates the number and multiplication of two variables

% and save the results

s = x + y;

p = x * y;

end

The function in Example3 can be called in the following way,

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