Mathematica Cookbook

Chapter 19. Debugging and Testing

Trying hard to speak and Fighting with my weak hand Driven to distraction So part of the plan When something is broken And you try to fix it Trying to repair it Any way you can I’m diving off the deep end You become my best friend I wanna love you But I don’t know if I can I know something is broken And I’m trying to fix it Trying to repair it Any way I can

—Coldplay, “X&Y”

19.0 Introduction

Debugging and testing are not as romantic as solving a difficult partial differential equation, creating a breathtaking plot, or achieving a compelling interactive demonstration of a complicated mathematical concept. But, to loosely paraphrase Edison, Mathematica creation is often 10% coding and 90% debugging and testing. Mathematica’s interactive development paradigm encourages incremental development, so often you proceed to solve a complex problem by writing little pieces, trying them, tweaking them, and repeating. In time, you will find yourself with quite a bit of code. Then, quite satisfied with yourself, you begin to feed your code real-world data and—bam!—something goes awry. Now what? 19.1 Printing as the First Recourse to Debugging through 19.6 Debugging Built-In Functions with Evaluation and Step Monitors demonstrate various debugging techniques that you can use from within the traditional Mathematica frontend. 19.7 Visual Debugging with Wolfram Workbench shows you how to use the powerful symbolic debugger provided by Wolfram Workbench.

Debugging skills ...