text: #include <Eigen/Dense>
  #include <iostream>
  
  using namespace Eigen;
  using namespace std;
  
  int main(int, char**)
  {
    cout.precision(3);
    typedef Matrix<float,3,3> Matrix3x3;
  Matrix3x3 m = Matrix3x3::Random();
  Matrix3f y = Matrix3f::Random();
  cout << "Here is the matrix m:" << endl << m << endl;
  cout << "Here is the matrix y:" << endl << y << endl;
  Matrix3f x;
  x = m.householderQr().solve(y);
  assert(y.isApprox(m*x));
  cout << "Here is a solution x to the equation mx=y:" << endl << x << endl;
  
    return 0;
  }
  