source: pacpussensors/trunk/Vislab/lib3dv/eigen/Eigen-install/doc/snippets/compile_HessenbergDecomposition_matrixH.cpp@ 136

#include <Eigen/Dense>
#include <iostream>

using namespace Eigen;
using namespace std;

int main(int, char**)
{
  cout.precision(3);
  Matrix4f A = MatrixXf::Random(4,4);
cout << "Here is a random 4x4 matrix:" << endl << A << endl;
HessenbergDecomposition<MatrixXf> hessOfA(A);
MatrixXf H = hessOfA.matrixH();
cout << "The Hessenberg matrix H is:" << endl << H << endl;
MatrixXf Q = hessOfA.matrixQ();
cout << "The orthogonal matrix Q is:" << endl << Q << endl;
cout << "Q H Q^T is:" << endl << Q * H * Q.transpose() << endl;

  return 0;
}