3D plot with range restricted to non-rectangular region

*To*: mathgroup at smc.vnet.net*Subject*: [mg66097] 3D plot with range restricted to non-rectangular region*From*: "David Sanders" <dpsanders at gmail.com>*Date*: Sat, 29 Apr 2006 03:40:54 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Hi, I want to plot a function whose range is naturally restricted to a non-rectangular region: h[x_, y_, z_] := Log[x] + Log[y] + Log[z] h2[x_, y_] := h[x, y, 1 - x - y] Only the region {(x,y): 0<x<1; 0<y<1-x} is allowed. If I try the naive Plot3D[h2[x, y], {x, 0, 1}, {y, 0, 1}] then I get error messages of the type: Plot3D::plnc: h2[x, y] is neither a machine-size real number at {x, y}={0.5, \ 0.5} nor a list of a real number and a valid color directive But then it plots the graph anyway. I also need contour plots of functions like this. Is there a proper way of avoiding these error messages, like making it ignore points whenever they contain an illegal operation (here, Log of a negative number)? Thanks, David.