Example showing how to add two Eigen::Quaterniond values

quaternionAdditionExample.cpp

Eigen::Quaterniond myQuaternion; //This is the quaternion we want to store the result in

//These are the two quaternions we'll be adding together
Eigen::Quaterniond q1 = initializeMyQuaternion(exampleParam); //We'll say it initializes to some random, valid vals
Eigen::Quaterniond q2 = initializeMyQuaternion(exampleParam2); 

//Perform the addition
myQuaternion.w() = q1.w() + q2.w(); //Add the scalar portion
myQuaternion.vec() = q1.vec() + q2.vec(); //Add the vector portion