ground/gcs/src/libs/eigen/doc/snippets/Tridiagonalization_diagonal.cpp

   1 MatrixXcd X = MatrixXcd::Random(4,4);
   2 MatrixXcd A = X + X.adjoint();
   3 cout << "Here is a random self-adjoint 4x4 matrix:" << endl << A << endl << endl;
   4
   5 Tridiagonalization<MatrixXcd> triOfA(A);
   6 MatrixXd T = triOfA.matrixT();
   7 cout << "The tridiagonal matrix T is:" << endl << T << endl << endl;
   8
   9 cout << "We can also extract the diagonals of T directly ..." << endl;
  10 VectorXd diag = triOfA.diagonal();
  11 cout << "The diagonal is:" << endl << diag << endl;
  12 VectorXd subdiag = triOfA.subDiagonal();
  13 cout << "The subdiagonal is:" << endl << subdiag << endl;