itpp库QR分解

1.程序源码

#include <itpp/itbase.h>

using namespace itpp;

using std::cout;
using std::endl;

int main()
{
        /*矩阵声明*/
        mat A, Q, R;

        /*使用字符串定义矩阵*/
        A = "12,-51,4; 6,167,-68; -4,24,-41;";

        /*A的QR分解结果*/
        qr(A, Q, R);

        /*打印结果*/
        cout << "A = " << A << endl;
        cout << "Q = " << Q << endl;
        cout << "R = " << R << endl;

        return 0;
}

2.编译源码

$ g++ -o example example.c -I/usr/local/include -L/usr/local/lib64 -litpp -lgfortran -lblas -llapack -lrefblas

3.运行结果

./example
A = [[12 -51 4]
 [6 167 -68]
 [-4 24 -41]]
Q = [[-0.857143 0.394286 0.331429]
 [-0.428571 -0.902857 -0.0342857]
 [0.285714 -0.171429 0.942857]]
R = [[-14 -21 14]
 [0 -175 70]
 [0 0 -35]]