ContourPlot and ColorFunction Opacity

*To*: mathgroup at smc.vnet.net*Subject*: [mg93714] ContourPlot and ColorFunction Opacity*From*: alpinekarst <alpinekarst at gmail.com>*Date*: Mon, 24 Nov 2008 04:10:51 -0500 (EST)

Dear All, I am hoping that one of the Gurus here can help me figure out how to adjust the opacity for a ContourPlot ColorFunction in Mathematica 6.0.3 say for example I have a 2D ContourPlot plot such as: ContourPlot[Cos[x y], {x, -Pi, Pi}, {y, -Pi, Pi}, GridLines -> Automatic, RegionFunction -> Function[{x, y, z}, Pi < x^3 + y^3 < Pi^3], BoundaryStyle -> Red, ColorFunction -> "TemperatureMap"] How can I adjust the Opacity of the filled region so that the gridlines are somewhat visible within the boundary defined by the RegionFunction? Using a constant would be fine or even better some generic decay function from the centroid of the region. I have tried defining the opacity in the color function multiple ways such as: {Directive[Opacity[0.5]], ColorData["TemperatureMap"][#1] &} but keep getting BoxForm and Graphics Directive errors. I'm thinking of resorting to replacement rules against AbsoluteOptions but that's bound to get ugly and I am hoping that there is a better way? This is probably quite simple...but not for me today. Thanks.

**Follow-Ups**:**RE : [mg93714] ContourPlot and ColorFunction Opaci***From:*"Jaccard Florian" <Florian.Jaccard@he-arc.ch>