Transform Quaternion

edit

Just to complete the previous response:

#include <tf/transform_datatypes.h>
// ...
tf::Quaternion q(quat.x, quat.y, quat.z, quat.w);
tf::Matrix3x3 m(q);
double roll, pitch, yaw;
m.getRPY(roll, pitch, yaw);
std::cout << "Roll: " << roll << ", Pitch: " << pitch << ", Yaw: " << yaw << std::endl;

Where quat contains the quaternion values to be transformed to roll, pitch, yaw.

It seems that creating a Matrix3X3 from the quaternion is not necessary since a transform already contains the rotation matrix. If you are working with TF, inside every Quaternion there is a Matrix3x3 called m_basis. When you call Transform::getRotation(), what you get is

From http://docs.ros.org/indigo/api/tf/htm... :

00120         Quaternion getRotation() const { 

00121                 Quaternion q;

00122                 m_basis.getRotation(q);

00123                 return q;

00124         }

So it could be that you may get away with:

transform.getBasis().getRPY(roll, pitch, yaw);