Similar to MIA ch09 RandomPointUtil.java, random selection is not uniform random.
org.apache.mahout.clustering.kmeans.RandonSeedGenerator.java problem
line 96-109
if (currentSize < k) {
//select
} else if (random.nextInt(currentSize + 1) != 0) { // with chance
1/(currentSize+1) pick new element
int indexToRemove = random.nextInt(currentSize); // evict one
chosen randomly
// replace with new
}
