MATLAB: Plot a elliptic cone

elliptic coneMATLAB

Hello there, I have this given equations of elliptic cone x^2 + 4*y^2 = z^2 and now I want to plot it.

I have try this but it seems to be incorrect.

f = @(x,y,z) x.^2 + 4*y.^2 - z.^2
fimplicit3(f,[-100,100])

How can I plot that function? Thanks in advance.

Best Answer

axis equal

Related Solutions

MATLAB: How to create a 3D cone

r = linspace(0,2*pi) ;
th = linspace(0,2*pi) ;
[R,T] = meshgrid(r,th) ;
X = R.*cos(T) ;
Y = R.*sin(T) ;
Z = R ;
surf(X,Y,Z)

MATLAB: How can i plot it

You have two surfaces:

theta = linspace(0,2*pi,30);
phi   = linspace(0,pi/2,30);
[theta,phi] = meshgrid(theta,phi);
r = 3;
[x,y] = sph2cart(theta,phi,r);
z_sphere = sqrt(9-x.^2-y.^2);
z_cone = sqrt(x.^2+y.^2);
%remove all complex elements
z_sphere(imag(z_sphere)>eps)=NaN;z_sphere=real(z_sphere);

They share the same coordinate grid, so now we can do element-wise operations. You need to remove points where z_sphere is higher than z_cone. The easiest way to remove points without messing up the coordinate grid is by marking them with NaN:

z_sphere( z_sphere>z_cone ) = NaN;
surf(x,y,z_cone,'FaceAlpha',0.3),hold on % optional line
surf(x,y,z_sphere)
view(45,45)

Best Answer

Related Solutions

MATLAB: How to create a 3D cone

MATLAB: How can i plot it

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