[JSL Contour Plot] Method of define contour plot, number, minimum, maximum

[#1]

The contour plot is very helpful to show 3D map, however the problem of defining the zone is always a trouble.

In my typical jsl plot, I use something below to define the contour plot zone number = 8, maximum = 1.4, minimum =1.

However, the table column :Length may change time to time, and the scale will have to be modified manually for each corresponding plot.

Does someone have experience how to create some jsl to define the contour plot minimum, maximum?

Ideally, it will be reasonable to define minimum = 25% quantile[length], and max = 75% quantile[length] for by group of age.

Thanks for the help

Contour Plot(
SendToByGroup( {:split== "age"} ),
X( :x, :y ),
Y( :Length),
Show Data Points( 0 ),
Fill Areas( 1 ),
Label Contours( 0 ),
Transform( "None" ),
Color Theme( "Spectral" ),
Specify Contours(
Min( 1 ),
Max( 1.4 ),
N( 8 ),
Contour( 1, 1, -6947008 ),
Contour( 2, 1.05714285714286, -1527295 ),
Contour( 3, 1.11428571428571, -42680 ),
Contour( 4, 1.17142857142857, -52812 ),
Contour( 5, 1.22857142857143, -5497088 ),
Contour( 6, 1.28571428571429, -14668544 ),
Contour( 7, 1.34285714285714, -15435520 ),
Contour( 8, 1.4, -16463106 ),
Contour( 9, 1.4, -10363169 )
));