// 创建稀疏矩阵 i j v 均为同长度的列矩阵
    private SparseMatrix Sparse(Matrix i, Matrix j, Matrix v)
    {
        SparseMatrix m = new SparseMatrix();

        for (int k = 0; k < i.rowLength; k++)
        {
            m.AddValue((int)i.elements[k][0], (int)j.elements[k][0], v.elements[k][0]);
        }
        return(m);
    }