Generating a circle.

So say I have an array of tiles:

Tile[] tiles = new Tile[100 * 100];

How would I generated a filled circle in that array?
I found some code in wiki, but it seems really complex and I can’t really understand it. It is called Midpoint circle algorithm. Does anyone have a good working circle generation algorithm?

http://groups.csail.mit.edu/graphics/classes/6.837/F98/Lecture6/circle.html

Thanks I will look into it.