1 Matrix3d m = 10000 * Matrix3d::Identity(); 2 m(0,2) = 1; 3 cout << "Here's the matrix m:" << endl << m << endl; 4 cout << "m.isDiagonal() returns: " << m.isDiagonal() << endl; 5 cout << "m.isDiagonal(1e-3) returns: " << m.isDiagonal(1e-3) << endl; 6 7