@Override
        public String getColumnName(int col) {
            switch (col) {
                case 0:
                    return "source";
                case 1:
                    return "colour";
                case 2:
                    return "x-axis";
                case 3:
                    return "y-axis";
                case 4:
                    return "x-min";
                case 5:
                    return "x-max";
                case 6:
                    return "y-min";
                case 7:
                    return "y-max";
            }
            return null;
        }