You can use matrices of dimension higher than four in other places. If you ever do work with physical stuff (that noisy, dirty real world thing), then you might wind up writing state transition equations that involve more than four variables. This is especially true in kalman filters, where you might be multiplying matrices of dimension ten (or higher; I'm using 16x16, but trying to slim it down...). I ended up writing a templated matrix class, which isn't too optimal, but it's really easy to work with. This is nice for variable sized matrices, since it's a real pain to have to write a seperate class for each possible dimension of matrix...

EDIT: typo...

[edited by - tsuraan on July 18, 2002 9:52:56 AM]