说明：  QR分解法是三种将矩阵分解的方式之一。这种方式，把矩阵分解成一个正交矩阵与一个上三角矩阵的积。QR 分解经常用来解线性最小二乘法问题。QR 分解也是特定特征值算法即QR算法的基础。
(QR decomposition are the three ways of decomposition of the matrix. In this way, the matrix decomposition into an orthogonal matrix and an upper triangular matrices. QR decomposition is often used for solving linear least squares problems. QR decomposition algorithm is given that QR eigenvalue algorithms.)