Programming with MATLAB

This is the version taught at the Software carpentries workshop beginning on Monday 18 November 2019.

The best way to learn how to program is to do something useful, so this introduction to MATLAB is built around a common scientific task: data analysis. Our real goal isn’t to teach you MATLAB, but to teach you the basic concepts that all programming depends on. We use MATLAB in our lessons because:

  1. we have to use something for examples;
  2. it’s well-documented;
  3. it has a large (and growing) user base among scientists in academia and industry; and
  4. it has a large library of packages available for performing diverse tasks.

But the two most important things are to use whatever language your colleagues are using, so that you can share your work with them easily, and to use that language well.

GNU Octave

GNU Octave is a free and open-source alternative to MATLAB which shares its syntax (see more about compatibility). Thus, if you don’t have access to MATLAB, you can easily set up Octave on your computer and still work through the lesson.

Prerequisites

To begin tackling this lesson, you will need to:

Overview of the data

We are studying inflammation in patients who have been given a new treatment for arthritis, and need to analyze the first dozen data sets. The data sets are stored in Comma Separated Values (CSV) format: each row holds information for a single patient, and the columns represent successive days. The first few rows of our first file, inflammation-01.csv, look like this:

0,0,1,3,1,2,4,7,8,3,3,3,10,5,7,4,7,7,12,18,6,13,11,11,7,7,4,6,8,8,4,4,5,7,3,4,2,3,0,0
0,1,2,1,2,1,3,2,2,6,10,11,5,9,4,4,7,16,8,6,18,4,12,5,12,7,11,5,11,3,3,5,4,4,5,5,1,1,0,1
0,1,1,3,3,2,6,2,5,9,5,7,4,5,4,15,5,11,9,10,19,14,12,17,7,12,11,7,4,2,10,5,4,2,2,3,2,2,1,1
0,0,2,0,4,2,2,1,6,7,10,7,9,13,8,8,15,10,10,7,17,4,4,7,6,15,6,4,9,11,3,5,6,3,3,4,2,3,2,1
0,1,1,3,3,1,3,5,2,4,4,7,6,5,3,10,8,10,6,17,9,14,9,7,13,9,12,6,7,7,9,6,3,2,2,4,2,0,1,1

We want to:

To do all that, we’ll have to learn a little bit about programming.

Follow On

MATLAB access for the University of Birmingham

Schedule

Setup Download files required for the lesson
00:00 1. Working With Variables How can I store values and do simple calculations with them?
01:05 2. Arrays How can I access subsets of data?
01:25 3. Plotting data How can I process and visualize my data?
02:00 4. Writing MATLAB Scripts How can I save and re-use my programs?
02:35 5. Repeating With Loops How can I repeat the same operations on multiple values?
03:25 6. Making Choices How can programs do different things for different data values?
04:05 7. Creating Functions How can I teach MATLAB how to do new things?
05:10 8. Defensive Programming How can I make sure my programs are correct?
05:40 Finish

The actual schedule may vary slightly depending on the topics and exercises chosen by the instructor.