There are 3 columns in the simulation (above attached jar file).
It seems that you are talking about the center column (the trajectory was shown from top to bottom)
Do you mean you want to change the particle to move from left to right for the center column?
In that case, you need to switch x,y , but you might need to change the orientation of the view, too!
I would suggest you provide a simple drawing so that we can know what you really want to do,
and we will try to guide you do it!