how can i plot 3D ellipsoid

Hi

I would like to plot a 3D ellipsoid without matlab's functions and thanks to an implicit equation

Best regard

[James Tursa]

"... without matlab's functions ..."

What does this mean? As written, this is impossible.

[Marsu567]

Sans utiliser une fonction ou fontionnalité préprogrammée dans matlab tel ellipsoid() ou fimplicit() ou autres

Merci

Answer 1

[Ameer Hamza]

Try this

a = 1;
b = 0.5;
c = 2;

f = @(x,y,z) (x/a).^2 + (y/b).^2 + (z/c).^2 - 1;

fimplicit3(f, [-3 3 -3 3 -3 3]);
axis equal

[Marsu567]

Merci

[Marsu567]

 x = -1:1/100:1;
 z = -1: 2/100 :1;
 N = length(x);
 N1 = length(z);
 Zc = zeros(N1,N);
 Xc = zeros(N1,N);
 for i = 1:N
 for j = 1:N1
    [Xc, Yc] =meshgrid(x,z);
    Zc(j,i) =sqrt(1-(Xc(j,i).^2)/2-(Yc(j,i).^2)/2)/2;
 end 
 end 
 Xc = 0.05*Xc;
 Yc = Yc;
 Zc = 0.05*Zc;
 
 
 

 surf(Xc, Yc, Zc)

[Euclides]

quick question....... is it possible to replicate this sort of plot by using only the ellipsoidal radius (i.e, a function of theta, phi, a, b, and c)? For instance, for the ellipse, I can use the elliptical radius in polar coordinates (function of phi, a and b) and then use the in-built polarplot function to visualize ellipses of various shapes. I am looking for something equivalent for the ellipsoid case, but haven't found it so far. There is the in-built ellipsoid function, but that uses Cartesian coordinates and I want to directly use the ellipsoidal radius function. Any help is very welcome!