public void addData(ArrayList<String> cells) {
		if (cells.size() != attribute.size())
			throw new IllegalArgumentException("Wrong size on row, was "
					+ cells.size() + " expected " + attribute.size());
		String[] row = cells.toArray(new String[0]);
		HashMap<String, String> newRow = new HashMap<String, String>();
		for (int i = 0; i < row.length; i++) {
			newRow.put(attribute.get(i), row[i]);
		}
		rows.add(newRow);

		String rowGoal = newRow.get(goalAttribute);
		Integer i = frequenzy.get(rowGoal);
		if (i == null) {
			i = 0;
		}
		i++;
		frequenzy.put(rowGoal, i);
	}