Better code through visualization

Visualization (which is different from virtualization) renders complex data into a simpler and easier-to-understanf form. We see it all the time with charts and graphs for business and economic activity, demographic trends, and other types of analysis. The pretty charts and graphs (and animated displays, for some analyses) summarize the data and make the trends or distribution clear.

The human brain is geared for visual input. We devote a significant chunk of the brain to the work of processing images.

We're now ready to use visualization (and by doing so, leveraging the brain's powerful capabilities) for software.

I'm doing this, in a very limited (and manual) way, by analyzing source code and creating object diagrams, maps of the different classes and how they relate. These maps are different from the traditional class hierarchy diagrams, in that they show references from methods. (The classic class diagrams show only references in member lists. I pick through the code and find "local" objects and show those references.)

The result is a class diagram that is more comprehensive, and also a bit messier. My process creates maps of classes with arrows showing the dependencies, and even simple (non-trivial) programs have a fair number of classes and a bunch more arrows.

The diagrams are useful. It is easy to spot classes that are not referenced, and contain dead code. I can also spot poorly-designed classes; they usually exist in a set with a "loop" of references (class A refers to class B, class B refers to class C, and class C refers to class A). The diagram makes such cyclic references obvious. It also makes a proper solution (when applied) obvious.

I'm adding the technique and the programs that make it possible to my toolbox of utilities. Visual analysis of programs helps me write better programs, and helps other members of the team understand our programs.

I'm not alone in this idea.

The ACM (the Association for Computing Machinery) ran an article on "code maps" in the August 2010 issue of their Communications magazine. (The name "Communications" refers to information shared with ACM members and does not denote the telecommunications aspect of computing.) The study team found that code maps help team members stay "oriented" within the code.

IBM has their "Many Eyes" project which can analyze data (not just source code) but I'm sure that they are close to visualization of code.

The IEEE (Institute for Electrical and Electronics Engineers) has their "VisWeek", an amalgam of conferences for visualization including the ACM SoftVis conference.

It's an idea whose time has come.