Long time back I had a chance to work on dimensionality reduction which deals with processing data that falls in large sets. The basic idea behind it is that it processes the data through a few steps to orient it in the way that most information can be calculated from it.
It
It works pretty fine for matrices as well and is used largely. The best part is that you need not even program it as there are standard libraries available for it already.Major Major mathematical tools like Matlab and Mathematica also support this functionality straight forwardlystraightforwardly.
There
There are two main algorithms that achieve this - Principal Component Analysis and Singular Value Decomposition.
What
What these algorithms actually achieve is finding that data that actually affects your reading by a significant margin.Internet The internet is full withof information on these algorithms.The next link This will show you how Apache is doing it. Apache Link