Re: Question about Plotting with boundary constriants

*To*: mathgroup at smc.vnet.net*Subject*: [mg58248] Re: Question about Plotting with boundary constriants*From*: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>*Date*: Fri, 24 Jun 2005 02:50:16 -0400 (EDT)*Organization*: The Open University, Milton Keynes, England*References*: <d9e0pk$gce$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

HUAFANG CUI wrote: > 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 > Hi, Have a look at the functions *Boole* (if you have Mathematica 5.1) or *UnitStep*. For example First we define a function of two variables, say In[1]:= f[x_, y_] := Sin[x]^2 + Cos[y] Then we plot it with your boundary conditions In[2]:= Plot3D[f[x, y]*Boole[0 <= y <= 1 - x], {x, 0, 1}, {y, -1, 1}]; Best regards, /J.M.