ROS difference btw setRotation() and getRotation() in tf::Matrix3x3

set_get_comparison.cpp

#include <iostream>
#include <tf/tf.h>

void coutQuaternion(tf::Quaternion q){
  std::cout<<q.getX()<<", "<<q.getX()<<", "<<q.getZ()<<", "<<q.getW()<<std::endl;
}

void coutTfMat(const tf::Matrix3x3& mat){
  std::cout<<mat[0][0]<<mat[0][1]<<mat[0][2]<<std::endl;
  std::cout<<mat[1][0]<<mat[1][1]<<mat[1][2]<<std::endl;
  std::cout<<mat[2][0]<<mat[2][1]<<mat[2][2]<<std::endl;
}
int main(){

  tf::Quaternion q_test(0.9698573, 0.0, 0.0242464, 0.2424643);
  tf::Matrix3x3 mat(q_test);
  coutTfMat(mat);
//  [  0.9988242, -0.0117578,  0.0470312;
//     0.0117578, -0.8824221, -0.4703116;
//     0.0470312,  0.4703116, -0.8812463 ]
  tf::Quaternion q_test2(0.3697843, -0.9244608, 0.0092446, 0.0924461);
//  [ -0.7094265, -0.6854115, -0.1640885;
//    -0.6819930,  0.7263482, -0.0854628;
//     0.1777626,  0.0512777, -0.9827365 ]
  std::cout<<"Before: ";
  coutQuaternion(q_test2);
  mat.setRotation(q_test2);
  std::cout<<"After setRotation(): ";
  coutQuaternion(q_test2);
  coutTfMat(mat);
  mat.getRotation(q_test);
  std::cout<<"After getRotation(): ";
  coutQuaternion(q_test);
  return 0;
}
// Result in terminal...
// 
// 0.998824-0.01175780.0470311
// 0.0117578-0.882422-0.470312
// 0.04703110.470312-0.881246
// Before: 0.369784, 0.369784, 0.0092446, 0.0924461
// After setRotation(): 0.369784, 0.369784, 0.0092446, 0.0924461
// -0.709427-0.685411-0.164089
// -0.6819930.726348-0.0854628
// 0.1777630.0512777-0.982737
// After getRotation(): -0.369784, -0.369784, -0.0092446, -0.0924461