getScale(id).unselect() (since PennController 1.6)
Will unselect the option currently selected.
If the scale is a slider, it will set it back to the central value.
newScale("score", 10) .print() , newButton("Unselect") .settings.callback( getScale("score").unselect() ) .print()
Prints a 10-point radio button scale and a button reading Unselect which, when clicked, unselects the currently selected button on the scale.