October 2012

Rapidly Computing the Standard Deviation for a Fixed Period (Length of Data)

Wikipedia’s page for Standard Deviation presents a formula for rapidly calculating the standard deviation of a growing set of numbers:

[1] Qk = Qk-1 + (xk – Ak-1)(xk – Ak) where xk is the kth element in the set and Ak is the mean of the first kth numbers.

The standard deviation squared of the first n numbers of a set is Qn / n.

From this, it is easy … Read more

List of MSN Gaming Zone Backgammon Cheaters

[Update: MSN has removed Backgammon from its games. Probably because of the rampant cheating. For a more fair place to play Backgammon that minimizes the chance of cheating (particularly because of the availability of instant replays) try]

Figured I’d compile this list after seeing several cheaters that … Read more