private Pair<int, int> max(DoubleMatrix2D matrix)
        {
            if (matrix == null)
            {
                return null;
            }

            int row = 0;
            int column = 0;
            double value = 0;

            for (int r = 0; r < matrix.rows(); r++)
            {
                for (int c = 0; c < matrix.columns(); c++)
                {
                    double currentValue = matrix.getQuick(r, c);
                    if (currentValue > value)
                    {
                        value = currentValue;
                        row = r;
                        column = c;
                    }
                }
            }

            if (value > 0)
            {
                return new Pair<int, int>(row, column);
            }
            else
            {
                return null;
            }
        }