I think this does require some scripting. You can go the "maybe works" way of using JMP's property viewer to get a reference and then set your close orientation
or use XPath (which I would most likely always use) to get the references to ColumnSwitcherContextOutlineBox (? OutlineBox would be much nicer) and then send messages to those as needed.
Names Default To Here(1);
dt = Open("$SAMPLE_DATA/Big Class.jmp");
gb = dt << Graph Builder(
Size(525, 454),
Show Control Panel(0),
Variables(X(:weight), Y(:height), Overlay(:sex)),
Elements(Points(X, Y, Legend(9)), Line Of Fit(X, Y, Legend(11))),
Column Switcher(:sex, {:name, :sex}),
Column Switcher(:weight, {:age, :weight})
);
obs = (gb << top parent) << XPath("//ColumnSwitcherContextOutlineBox");
obs << Close(1);
wait(1);
obs << Outline Close Orientation("Horizontal");
// obs << Outline Close Orientation("Vertical");
In some cases you might need to modify the XPath query to work but in this simple case using JMP17.2 this did work.
Might be worth sending message to support so that would also be recorded as part of column switcher like Jim did mention. @julian
-Jarmo