Knn Boundary Visualization with Processing.js

I have known Processing for quite a while as a programming language for quick prototyping graphically interactive programs. But not until recently that I realized it is also capable of exporting into a Javascript program through Processing.js (already built into the Processing IDE). What this means is that you can write a Processing program once and have it run on the usual Java platforms as well as web browsers supporting Javascript (provided that no external Processing library is used).

Here is my little implementation of Knn boundary visualizer. I did this just to get a feel of Processing.js.

I found the process of composing the code to be pleasant. This is perhaps partially because of the similarity to Java which I am already familiar. One thing worth mentioning though is that, TBOMK, without an external library, Processing.js does not support any UI component (i.e., button, combo box). Everything above was achieved by drawing, which is a bit painful if you have many buttons; as you need to manually specify the coordinates to draw. This will pose an even more serious problem if the effect of a text field is desired. The only thing provided is the facility to capture keys. Then, you are on your own for the rest. Apparently it takes a lot of patience to write code to simulate the blinking cursor of a text field. Optimistically I am pretty sure someday there will be a library for UI components in Processing.js.

Download: Source code