I have two parameters in my visualization (one on each vertical axis). I want it so that if "None" is selected in the Parameter control that no data will appear. Currently, when "None" is selected and I set it to be Null, it just shows a value of zero instead of being blank.
I can't think of any way around not showing a 0, even when the value is Null. Since it is a measure, Tableau wants to give it a numerical axis and since it is null, the natural point to show is 0. This might be a good one to add to the Ideas section!