I am not aware of an option to change the whisker length of the box plot in JMP. However, the JMP capability of being able to add graphics to the graphical output in JMP, would permit the calculation and displaying of whiskers of a different length.
Here is the start of how to approach the adding of new whiskers to a box plot. The example is very hard wired, where a real script would have to calculate the 3.0 IQR and then draw the required lines.
names default to here(1);
dt =
// Open Data Table: Big Class.jmp
// → Data Table( "Big Class" )
Open( "$SAMPLE_DATA/Big Class.jmp" );
gb = Graph Builder(
Variables( X( :sex ), Y( :height ) ),
Elements( Box Plot( X, Y, Legend( 4 ) ) ),
SendToReport(
Dispatch(
{},
"400",
ScaleBox,
{Legend Model(
4,
Base( 1, 0, 0, Item ID( "height", 2 ) ),
Properties(
1,
{Line Color( 3 ), Fill Color( 0 )},
Item ID( "height", 2 )
)
)}
),
Dispatch(
{},
"Graph Builder",
FrameBox,
{DispatchSeg( Box Plot Seg( "Box Plot (F)" ), Fences( 0 ) ),
DispatchSeg( Box Plot Seg( "Box Plot (M)" ), Fences( 0 ) )}
)
)
);
report(gb)[FrameBox(1)] << Add Graphics Script(
line({0,63.5},{0,70});
line({-.20,70},{.20,70});
);
Jim