// 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);
}