OpenGL is powerful, but it can also be more complicated than actually necessary. For applications involving 2D graphics, a low amount of interactivity, and a smaller amount of data, it would be simpler not to bother with the video card and the rendering pipeline. Additionally, some visualizations are meant for print form. The Gnome Foundation’s Cairo 2D graphics toolkit is perfect for these applications. As luck would have it, Haskell also has an excellent binding to Cairo.
Three other things make Haskell ideally suited to information visualization and visual analytics: a well-thought out and extensible library of generic data structures, lazy evaluation, and the separation of data transformation code from input/output inherent in a pure functional programming language. Visualizations written in Haskell tend naturally to break up into portions of reusable and visualization specific code. Thus, programs for visualization written in Haskell maintain readability and reusability as well or better than Python, but do not suffer the performance problems of an interpreted language.
For much the same reason as Simon Peyton-Jones put together Tackling the Awkward Squad, I have put together these lecture notes. I hope these will bring a programmer interested in visualization and open to the aesthetic advantages of functional programming up to speed on both topics.
