i value the stuff you have posted on FTR. This one is less valuable for me, but it's gold for those who need it! very nice post.

-> beginners circle. If you are scared of the math, don't be. Work your way through this post, one section at a time. If you get stuck then jump into IRC, you'll get help. But try first, this is very well presented and there is a good chance you'll manage to get through it.