how to: geom calcs in ROS

edit

I'm in the need to do geometry calculations (matrix_by_matrix, vector_by_matrix, scalar_by_vector, and so on).

I looked up the documentation but the vector class isn't documented at all, and doing something like

tf::Vector3 myvect = vect1 + vect2;

results in error, as well as

tf::Vector3 myvect;
myvect.x = 3.5;

or

tf::Vector3 myvect(1,2,3);
myvect = myvect * 2;

So Vector3 appears to be unusable. Why are all those types there if I eventually must use Eigen?

Here is my code:

    tf::StampedTransform transform1, transform2, transform3;
    tf::Vector3 vactual1, vactual2, vactual3, cmd1, cmd2, cmd3, *tmp1, *tmp2, *err;
    tf::Quaternion qactual1,qactual2,qactual3;
    double roll,pitch,yaw, dist12, dist13, dist23, factor;
    while (n.ok())
    {        

        try{
            listener.lookupTransform("world", "/robot_1/base_link", ros::Time(0), transform1);
            listener.lookupTransform("world", "/robot_2/base_link", ros::Time(0), transform2);
            listener.lookupTransform("world", "/robot_3/base_link", ros::Time(0), transform3);
        vactual1 = transform1.getOrigin();
        vactual2 = transform2.getOrigin();
        vactual3 = transform3.getOrigin();
        qactual1 = transform1.getRotation();
        qactual2 = transform2.getRotation();
        qactual3 = transform3.getRotation();
        tf::Matrix3x3(qactual1).getRPY(roll, pitch, yaw);
        dist12 = (powf(vactual2.x()-vactual1.x(),2)+powf(vactual2.y()-vactual1.y(),2));
        dist13 = (powf(vactual3.x()-vactual1.x(),2)+powf(vactual3.y()-vactual1.y(),2));
        dist23 = (powf(vactual3.x()-vactual2.x(),2)+powf(vactual3.y()-vactual2.y(),2));

    //compute error correction for node 1
    err = new tf::Vector3(vactual2.x() - vactual1.x(),vactual2.y() - vactual1.y(), 0);
    factor = - 0.5 * (dist12 - 1.0);
    tmp1 = new tf::Vector3(factor * err->x(), factor * err->y(), 0);
    err = new tf::Vector3(vactual3.x() - vactual1.x(), vactual3.y() - vactual1.y(), 0);
    factor = - 0.5 * (dist13 - 1.0);
    tmp2 = new tf::Vector3(factor * err->x(), factor * err->y(), 0);
    cmd1 = *tmp1 + *tmp2;

    //compute error correction for node 2
    err = new tf::Vector3(vactual1.x() - vactual2.x(), vactual1.y() - vactual2.y(), 0);
    factor = - 0.5 * (dist12 - 1.0);
    tmp1 = new tf::Vector3(factor * err->x(), factor * err->y(), 0);
    err = new tf::Vector3(vactual3.x() - vactual2.x(), vactual3.y() - vactual2.y(), 0);
    factor = - 0.5 * (dist23 - 1.0);
    tmp2 = new tf::Vector3(factor * err->x(), factor * err->y(), 0);
    cmd2 = *tmp1 + *tmp2;

    //compute error correction for node 3
    err = new tf::Vector3(vactual2.x() - vactual3.x(), vactual2.y() - vactual3.y(), 0);
    factor = - 0.5 * (dist23 - 1.0); 
    tmp1 = new tf::Vector3(factor * err->x(), factor * err->y(), 0);
    err = new tf::Vector3(vactual1.x() - vactual3.x(), vactual1.y() - vactual3.y(), 0);
    factor = - 0.5 * (dist13 - 1.0);
    tmp2 = new tf::Vector3(factor * err->x(), factor * err->y(), 0);
    cmd3 = *tmp1 + *tmp2;

    }
    catch (tf::TransformException ex){
            ROS_ERROR("%s",ex.what());
        }


    std::cout << "Robot 1 -> X: " << vactual1.x() << "  Y: " << vactual1.y() << "  T: " << yaw << std::endl;
    std::cout << "Formation : [" << dist12 << " , " << dist13 << " , " << dist23 << "]" << std::endl;
        ros::spinOnce();
        r.sleep();
    }

As is evident from the above I had to find workarounds for many of the operations: scalar_by_vector wasn't accepted, and not knowing how to set a member I had to move math operations inside instantiation instructions.