How to set the X Y Z position attributes of a DC



I’m having trouble setting the X Y Z position attributes of a selected DC.
I’m trying for example to set a Y position attribute to ‘5000’. or to refer to some other attribute…

get_attribute works fine.
set_attribute gives me a silent error - does nothing.

The outcome I eventually want is to change the formulas within the X Y Z of the selected DC to some other ones.
I’ve tried using .to_s, .to_f … doesn’t seem to help.
Am I referring to the wrong attributes? Wrong definition!?

(With setting LenX LenY LenZ I have no problems - it’s with the positions it doesn’t work).

def set_att_test
    # begining of undo
    model = Sketchup.active_model
    # select only DCs    
    model.selection.grep(Sketchup::ComponentInstance) { |entity| 
    next unless entity.definition.attribute_dictionary('dynamic_attributes', false)

        # apply the following on selected DCs
        # get attribute
        y_formula = entity.definition.get_attribute('dynamic_attributes', '_inst__y_formula')
        puts y_formula #<= this works
        entity.definition.set_attribute('dynamic_attributes', '_inst__y_formula', '5000') #<= does not work
        entity.definition.set_attribute('dynamic_attributes', '_y_formula', '5000') #<= does not work

        # redraw
        dcs = $dc_observers.get_latest_class

    model.commit_operation # end of undo




I think I got it…
(As usual when asking a question, the solution comes right up)

entity.definition.set_attribute('dynamic_attributes', '_y_formula', '5000')

entity.set_attribute('dynamic_attributes', '_y_formula', '5000')

And the _inst__y_formula is updated as expected… so no need to set it.