ITuple T = (ITuple) dataValues.get(i);
xvalues[i] = ((INumber) T.get(0)).toReal().doubleValue();
}
// Create a natural ranking: largest first.
double rank[] = new NaturalRanking().rank(xvalues);
for(int i = 0; i < rank.length; i++){
rank[i] = rank.length - rank[i] + 1; // invert the ranking: smallest come now first.
//System.err.println("rank[" + i + "] = " + rank[i]);
}