Re: ContourPlot ColorFunction Question

*To*: mathgroup at smc.vnet.net*Subject*: [mg119439] Re: ContourPlot ColorFunction Question*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Sat, 4 Jun 2011 06:19:10 -0400 (EDT)

For ContourPlot, there is only one argument for ColorFunction. That argument is the contour levels. ContourPlot[x^2 + c - x, {c, -2, 2}, {x, -2, 2}, ColorFunction -> (If[# > 0, Red, Green] &), Contours -> {0}] Plot[ Evaluate[x /. Solve[x^2 + c == x, x]], {c, -2, 2}, Frame -> True, Axes -> False, PlotRange -> {-2, 2}, AspectRatio -> 1, PlotStyle -> {Green, Red}] Plot[ x /. Solve[x^2 + c == x, x], {c, -2, 2}, Frame -> True, Axes -> False, PlotRange -> {-2, 2}, AspectRatio -> 1, ColorFunction -> (If[2 #2 > 1, Red, Green] &)] Bob Hanlon ---- Jody Sorensen <jodo11 at yahoo.com> wrote: ============= I'm new to this list and possibly out of my depth, but I'd appreciate any help on this issue. We are trying to plot an implicit function using ContourPlot and have the points on the curve colored based on the x and y values (which we call c and x) - specifically based on the value of the derivative. We have tried things like the following without success, even though similar commands work with Plot: ContourPlot[x^2+c = x, {c, -2, 2}, {x, -2, 2}, ColorFunction -> (If[2 #1 > 1, Red, Green] &)] Any suggestions or solutions would be great to hear! Thanks! Jody Sorensen