Re: Question about Plotting with boundary constriants

*To*: mathgroup at smc.vnet.net*Subject*: [mg58236] Re: [mg58225] Question about Plotting with boundary constriants*From*: "David Park" <djmp at earthlink.net>*Date*: Fri, 24 Jun 2005 02:49:55 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

HC, There was a similar question on MathGroup just two weeks ago. http://forums.wolfram.com/mathgroup/archive/2005/Jun/msg00496.html One method is to multiply your function f[x,y] by a Boole function defining the triangular region. This gives a somewhat jagged boundary to the boundary region. To make it reasonably smooth you have to go to a large number of PlotPoints, which also generally forces you to get rid of the 'mesh'. The methods I presented in the link above uses two different methods to give a smooth boundary region with a normal number of PlotPoints. One method uses variable substitution to turn a variable domain iterator into a fixed domain interator and then uses ParametricPlot3D to plot the function. The second method uses a grid of polygons that fits the boundary and then raises the grid to a 3D surface. Both of these methods use the DrawGraphics Mathematica package at my web site below. David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: HUAFANG CUI [mailto:huafangc at seas.upenn.edu] To: mathgroup at smc.vnet.net Hi, I have a question about plotting a 3d graph with some boundary constraints. for example, feasible area of function f(x, y) is 0 <= x <= 1 and 0 <= y <= 1-x. Thanks alot. HC