Using Matlab I do some inverse kinematics calculations to get joint values for an arm. I then want to "command" the joints in my RViz model to move to those values.

Being very new to the ROS environment I was hoping that this could be done by publishing the Matlab values to one of the topics that appear when I launch the demo.launch file. However, looking at the different topics and their message types, it, to me, is not obvious which one I should publish to (if this is the right approach).

I can see the following topics:

/attachedcollisionobject
/collisionobject
/executetrajectory/cancel
/executetrajectory/feedback
/executetrajectory/goal
/executetrajectory/result
/executetrajectory/status
/headmountkinect/depthregistered/points
/jointstates
/movegroup/cancel
/movegroup/displaycontacts
/movegroup/displaycostsources
/movegroup/displaygraspmarkers
/movegroup/displayplannedpath
/movegroup/fakecontrollerjointstates
/movegroup/feedback
/movegroup/filteredcloud
/movegroup/goal
/movegroup/monitoredplanningscene
/movegroup/motionplanrequest
/movegroup/ompl/parameterdescriptions
/movegroup/ompl/parameterupdates
/movegroup/planexecution/parameterdescriptions
/movegroup/planexecution/parameterupdates
/movegroup/planningscenemonitor/parameterdescriptions
/movegroup/planningscenemonitor/parameterupdates
/movegroup/result
/movegroup/senseforplan/parameterdescriptions
/movegroup/senseforplan/parameterupdates
/movegroup/status
/movegroup/trajectoryexecution/parameterdescriptions
/movegroup/trajectoryexecution/parameterupdates
/pickup/cancel
/pickup/feedback
/pickup/goal
/pickup/result
/pickup/status
/place/cancel
/place/feedback
/place/goal
/place/result
/place/status
/planningscene
/planningsceneworld
/recognizedobjectarray
/rosout
/rosoutagg
/rviz/moveit/execute
/rviz/moveit/plan
/rviz/moveit/selectplanninggroup
/rviz/moveit/stop
/rviz/moveit/updatecustomgoalstate
/rviz/moveit/updatecustomstartstate
/rviz/moveit/updategoalstate
/rviz/moveit/updatestartstate
/statistics
/tf
/tfstatic
/trajectoryexecution_event

Thanks in advance!