Programming and Data Types

What's in an M-File?

This section shows you the basic parts of a function M-file, so you can familiarize yourself with MATLAB programming and get started with some examples.

• function f = fact(n) % Function definition line
  % FACT Factorial.    % H1 line
  % FACT(N) returns the factorial of N, H! % Help text
  % usually denoted by N!
  % Put simply, FACT(N) is PROD(1:N).
  
  f = prod(1:n);       % Function body
  

This function has some elements that are common to all MATLAB functions:

• A function definition line. This line defines the function name, and the number and order of input and output arguments.
• An H1 line. H1 stands for "help 1" line. MATLAB displays the H1 line for a function when you use lookfor or request help on an entire directory.
• Help text. MATLAB displays the help text entry together with the H1 line when you request help on a specific function.
• The function body. This part of the function contains code that performs the actual computations and assigns values to any output arguments.

Refer to Functions for more detail on the parts of a MATLAB function.

Kinds of M-Files

Providing Help for Your Programs