The main parameters for the above simulation are x and y.
and , (cta is the variable for )
You can find the above relations from [b]constraints[/b] page in EJS.
If you want to add slider or numerical input for r (to change r by slider or numerical input).
you need to add code (at On drag property: i.e what need to be changed when the slider were dragged).
You can add the following code for the [b]Drag Action[/b] for the slider
However, you need to change
in Custom page to
and add a new variable r in the variable page (so that you can use it in view too).