auto euler = q.toRotationMatrix().eulerAngles(0, 1, 2);

std::cout << "Euler from quaternion in roll, pitch, yaw"<< std::endl << euler << std::endl;

using namespace Eigen;

//Roll pitch and yaw in Radians

float roll = 1.5707, pitch = 0, yaw = 0.707;    

Quaternionf q;

q = AngleAxisf(roll, Vector3f::UnitX())

    * AngleAxisf(pitch, Vector3f::UnitY())

    * AngleAxisf(yaw, Vector3f::UnitZ());

std::cout << "Quaternion" << std::endl << q.coeffs() << std::endl;