At Wednesday, 06 February 2002, you wrote: >However, the real answer to your problem is to form your >lines as Gridded2DSets (if you want lines in 2-D) or >Grided3DSets (if you want lines in 3-D), in either case >with manifold dimension = 1. You can combine multiple >lines in a UnionSet. To get color, use your Set as the >domain Set of a FlatField with MathType (e.g., in the >3-D case): > > ((x, y, z) -> (r, g, b)) > >In your Display, map x -> XAxis, ..., r -> Red, ... >In your FlatField, set color values into r, g & b via >setSamples(). Could you apply this to the Rivers example? Then I think I would understand it. Rivers.java already uses a Unionset, so if you could take it from there and make one tributary red and another one blue. .