Can the vertical dividing line of the X-axis in the drawing only show part of it?

[#1]

Thanks Experts!

dt=Open("$SAMPLE_DATA/Big Class.jmp");
p1=dt<< Graph Builder(
	Size( 534, 455 ),
	Show Control Panel( 0 ),
	Variables(
		X( Transform Column( "Row", Formula( Row() ) ) ),
		Y( :height ),
		Y( :weight )
	),
	Elements( Position( 1, 1 ), Line( X, Y, Legend( 5 ) ) ),
	Elements( Position( 1, 2 ), Bar( X, Y, Legend( 7 ) ) ),
	SendToReport(
		Dispatch(
			{},
			"Row",
			ScaleBox,
			{Add Ref Line( 10.5, "Dotted", "Dark Red", "", 1 ),
			Add Ref Line( 20.5, "Dotted", "Dark Red", "", 1 ),
			Add Ref Line( 30.5, "Dotted", "Dark Red", "", 1 )}
		)
	)
);

[#2 · Accepted solution]

I would suggest utilizing X/Y Origin() and X/Y Range() in cases like this

Names Default To Here(1);

dt = Open("$SAMPLE_DATA/Big Class.jmp");

dt << new column("R", Numeric, Continuous, Formula(Row()));

ar4 = [12.5, 22.5, 33.5];

gb = dt << Graph Builder(
	Size(534, 456),
	Show Control Panel(0),
	Variables(X(:R), Y(:height), Y(:weight)),
	Elements(Position(1, 1), Line(X, Y, Legend(11))),
	Elements(Position(1, 2), Bar(X, Y, Legend(14)))
);

Eval(EvalExpr(
	Report(gb)[FrameBox(2)] << Add Graphics Script(
		For Each({v}, Expr(ar4),
			Pen Color("red");
			Line Style("dashed");
			Line({v, Y Origin()}, {v, Y Origin() + Y Range()});
		);
	)
));

[#3]

After running the code, the chart appears, but an error message is displayed. Log:

Name Unresolved: For Each in access or evaluation of 'For Each' , For Each(
{v},
[12.5, 22.5, 33.5],
Pen Color( "red" );
Line Style( "dashed" );
Line( {v, Y Origin()}, {v, Y Origin() + Y Range()} );
) /*###*/

[#4]

What version of JMP are you using.  For each() was first implemented in JMP 16

Here is a version of the code that will work for JMP 15 and earlier

Names Default To Here( 1 );

dt = Open( "$SAMPLE_DATA/Big Class.jmp" );

dt << New Column( "R", Numeric, Continuous, Formula( Row() ) );

ar4 = [12.5, 22.5, 33.5];

gb = dt << Graph Builder(
	Size( 534, 456 ),
	Show Control Panel( 0 ),
	Variables( X( :R ), Y( :height ), Y( :weight ) ),
	Elements( Position( 1, 1 ), Line( X, Y, Legend( 11 ) ) ),
	Elements( Position( 1, 2 ), Bar( X, Y, Legend( 14 ) ) )
);

Eval(
	Eval Expr(
		Report( gb )[FrameBox( 2 )] << Add Graphics Script(
			For( i = 1, i <= N Items( ar4 ), i++,
				v = ar4[i];
				Pen Color( "red" );
				Line Style( "dashed" );
				Line( {v, Y Origin()}, {v, Y Origin() + Y Range()} );
			)
		)
	)
);

[#5]

V14.3, it is too old...

[#6]

JMP 14 was released in March of 2018.  Yes, it is pretty old.  However, The code I provided works in JMP 14