Joshua Menke

For many of you, this book will be your first exposure to scripting, the process of instructing MatLab what to do to your data. Although you will be learning something new, many other tasks of daily life will have already taught you relevant skills. Scripts are not so different than travel directions, cooking recipes, carpentry and building plans, and tailoring instructions. Each is in pursuit of a specific goal, a final product that has value to you. Each has a clear starting place and raw materials. And each requires a specific, and often lengthy, set of steps that need to be seen to completion in order to reach the goal. Put the skills that you have learned in these other arenas of life to use!

As a beginner, you should approach scripting as you would approach giving travel directions to a neighbor. Always focus on the goal. Where does the neighbor want to go? What analysis products do you want MatLab to produce for you? With a clear goal in mind, you will avoid the common pitfall of taking a drive that, while scenic, goes nowhere in particular. While MatLab can make pretty plots and interesting tables, you should not waste your valuable time creating any that does not support your goal.

When starting a scripting project, think about the information that you have. How did you get from point A to point B, the last time that you made the trip? Which turns should you point out to your neighbor as particularly tricky? Which aspects of the script are likely to be the hardest to get right? It is these parts on which you want to focus your efforts.

Consider the value of good landmarks. They let you know when you are on the right road (you will pass a firehouse about halfway) and when you have made the wrong turn (if you go over a bridge). And remember that the confidence-building value of landmarks is just as important as is error detection. You do not want your neighbor to turn back, just because the road seems longer than expected. Your MatLab scripts should contain landmarks, too. Any sort of output, such as a plot, that enables you to judge whether or not a section of a script is working is critical. You do not want to spend time debugging a section of your script that already works. Make sure that every script that you write has landmarks.

Scripts relieve you from the tedium of repetitive data analysis tasks. A finished script is something in which you can take pride, for it is a tool that has the potential for helping you in your work for years to come.

February, 2011