Programming and Data Types    

Program Development

This section covers the following topics:

Planning the Program

When planning how to write a program, take the problem you are trying to solve and break it down into a series of smaller, independent tasks. Implement each task as a separate function. Try to keep functions fairly short, each having a single purpose.

Using Pseudo-Code

You may find it helpful to write the initial draft of your program in a structured format using your own natural language. This pseudo-code is often easier to think through, review, and modify than using a formal programming language, yet it is easily translated into a programming language in the next stage of development.

Selecting the Right Data Structures

Look at what data types and data structures are available to you in MATLAB and determine which of those best fit your needs in storing and passing your data.

For more information: See Data Types in the MATLAB "Programming and Data Types" documentation

General Coding Practices

A few suggested programming practices:

Naming a Function Uniquely

To avoid choosing a name for a new function that might conflict with a name already in use, check for any occurrences of the name using this command:

For more information: See the which function reference page

The Importance of Comments

Be sure to document your programs well to make it easier for you or someone else to maintain them. Add comments generously, explaining each major section and any smaller segments of code that are not obvious. You can add a block of comments as shown here.

For more information: See Comments in the MATLAB "Programming and Data Types" documentation

Coding in Steps

Don't try to write the entire program all at once. Write a portion of it, and then test that piece out. When you have that part working the way you want, then write the next piece, and so on. It's much easier to find programming errors in a small piece of code than in a large program.

Making Modifications in Steps

When making modifications to a working program, don't make widespread changes all at one time. It's better to make a few small changes, test and debug, make a few more changes, and so on. Tracking down a difficult bug in the small section that you've changed is much easier than trying to find it in a huge block of new code.

Functions with One Calling Function

If you have a function that is called by only one other function, put it in the same M-file as the calling function, making it a subfunction.

For more information: See Subfunctions in the MATLAB "Programming and Data Types" documentation

Testing the Final Program

One suggested practice for testing a new program is to step through the program in the MATLAB debugger while keeping a record of each line that gets executed on a printed copy of the program. Use different combinations of inputs until you have observed that every line of code is executed at least once.

  Function Arguments Debugging