Re: ContourPlot3D and positive contours

*To*: mathgroup at smc.vnet.net*Subject*: [mg88300] Re: ContourPlot3D and positive contours*From*: Szabolcs Horvát <szhorvat at gmail.com>*Date*: Thu, 1 May 2008 03:20:02 -0400 (EDT)*Organization*: University of Bergen*References*: <fv9jtb$52h$1@smc.vnet.net>

guerom00 wrote: > Hello everyone :) > > Using the ContourPlot3D, how can I plot only the positive contours (or > only the negative ones for that matter=85) > I would imagine an option like this : > > ContourPlot3D[f,Contours->{#>0&,10}] > > which would plot the first 10 positive contours. But that does not > exist=85 > > Right now, I'm plotting the contours of the positive part of my > function like this : > > ContourPlot3D[1/2*(f+Abs[f]),Contours->{10}] > > but that's not pretty=85 > > Is there a better way to do this ? You could try using RegionFunction. Here's is an example: ContourPlot[x^3 - 3 y^2 x, {x, -3, 3}, {y, -3, 3}, RegionFunction -> Function[{x, y, f}, f > 0], Contours -> 20] This should be applicable to 3D as well.