A term originally created by male math geeks to easily rate women, without the ambiguity created by the single number rating.
Three numbers in the following order, the first for face, second for body, and the third binary, for whether or not you would do said individual, the last being highly subjective.
Usage has since expanded beyond its UC Berkeley origins to some areas of LA and throughout the University of Michigan Ann Arbor.
Note that the matrix terminology is due to its 3x1 properties, and "Ani" is added to the name because that was supposedly the nickname of one of the individuals popularizing the system.
Old: "Yo man. Check it. That chick is a definate 8"
"No way. She's a 7. She's got booty for both of us"
Animatrixed: "Yo man. Check it. 9 6 1. "
"Ay. 9 6 0. Chick needs to work that ass"