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