private String[] createcolumnNames(Integer nbrVars) {
		String[] columnNames = new String[nbrVars.intValue() + 2];
		columnNames[0] = "index";
		for (int i = 1; i < nbrVars.intValue() + 1; i++) {
			char c = (char) (64 + i);
			columnNames[i] = String.valueOf(c);
		}
		columnNames[nbrVars.intValue() + 1] = "S";
		return columnNames;
	}