How to plot a surface in its parametric form ?

Hello,

I have à problem when I try to plot a surface that has this form for exemple:

 0=<r=<infinite
 0=<t=<2*pi
x=r*cos (t)
y=r*sin (t)
z=(r^3)/6

This is the surface il want to plot but the value in z bother me. Indeed I can't use meshgrid because of that.

What can I do?

Thanks for your help !

Answer 1

[KSSV]

clc; clear all ;
M = 100 ; N = 100 ;
rinf = 100 ; % take rinf how big you want 
r = linspace(0,rinf,M) ; 
t = linspace(0,2*pi,N) ; 
[R T] = meshgrid(r,t) ;
X = R.*cos(T) ;
Y = R.*sin(T) ;
Z = R.^3/6 ;

surf(X,Y,Z) ;

[Loris Chavée]

So I'm supposed to use meshgrid With the two parameters of the surface ?

Answer 2

[José-Luis]

You don't need to use meshgrid() if you have the symbolic math toolbox.

See plotfunc3d.