Re: help!! Plot3D of ellipsoid

*To*: mathgroup at smc.vnet.net*Subject*: [mg4943] Re: [mg4908] help!! Plot3D of ellipsoid*From*: "Paul R. Wellin" <wellin>*Date*: Mon, 7 Oct 1996 02:02:12 -0400*Sender*: owner-wri-mathgroup at wolfram.com

> I am trying to get a 3-d plot of an ellipsiod, of the equation > > (x^2/a^2) + (y^2/b^2) + (z^2/c^2) = 1 > > manipulating the equation I can get > > z = (c^2 (1- (x^2/a^2) - (y^2/b^2)))^1/2 > > then, with the constants defined, I write > > Plot3D[z,{x,0,a},{y,0,b}] > > Mathematica then spits out a bunch of errors You will have to parametrize the surface. I'll leave the details to you, but with a bit of work, you can parametrize the ellipsoid as: In[1]:= ellipsoid[u_,v_] := {a Cos[u] Cos[v], b Sin[u] Cos[v], c Sin[v]} Then you can generate your surface as: In[2]:= a = 1; b = 1; c = 2; ParametricPlot3D[ellipsoid[u, v], {u, 0, 2 Pi}, {v, -Pi/2, Pi/2}] Out[2]= -Graphics3D- You can fiddle with the parameters to get stretch the ellipse in the x, y, or z directions. --- Paul Wellin Academic/Business Liaison Wolfram Research, Inc. 100 Trade Center Drive Champaign, IL 61820 phone: 217-398-0700 fax: 217-398-0747 email: wellin at wolfram.com ==== [MESSAGE SEPARATOR] ====