Linde-Buzo-Gray Algorithm

It's an algorithm in vector quantization to derive a good codebook. Similar to K-means method in data clustering.

The algorithm
At each iteration, each vector is split into two new vectors.


 * A initial state: centroid of the training sequence;
 * B initial estimation #1: code book of size 2;
 * C final estimation after LGA: Optimal code book with 4 vectors;
 * D initial estimation #2: code book of size 4;
 * E final estimation after LGA: Optimal code book with 4 vectors;