Piecewise ColorFunction

*To*: mathgroup at smc.vnet.net*Subject*: [mg125652] Piecewise ColorFunction*From*: Hugh Goyder <h.g.d.goyder at cranfield.ac.uk>*Date*: Sun, 25 Mar 2012 00:17:46 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

The first example below works to give a plot style with colours that vary with y-values. I then try to define a Piecewise function for the colour and this does not work. Am I doing something wrong? Thanks for any assistance. Plot[Sin[x], {x, 0, 4 Pi}, PlotStyle -> Thick, ColorFunction -> Function[{x, y}, ColorData["NeonColors"][y]]] ClearAll[f]; f[x_, y_] := Piecewise[{{Green, y < 0}, {Red, y >= 0}}] Plot[Sin[x], {x, 0, 4 Pi}, PlotStyle -> Thick, ColorFunction -> f]

**Follow-Ups**:**Re: Piecewise ColorFunction***From:*Bob Hanlon <hanlonr357@gmail.com>