How to draw a ball by plot3?

I am learning the MATLAB,

Answer 1

[DGM]

I choose to assume that a request to plot a solid volume with a line/point plotting tool should suggest that the usage of the term "ball" is informal and that a spherical shell is an acceptable interpretation of the wording:

nturns = 20;
pointsperturn = 50;
r = 1;
th = linspace(0,2*pi*nturns,pointsperturn*nturns);
phi = linspace(-pi/2,pi/2,pointsperturn*nturns);

[x y z] = sph2cart(th,phi,r);

plot3(x,y,z)
axis equal
grid on

[Xizeng Feng]

thank you very much!

Answer 2

[KSSV]

m = 100; n = 100; p = 100 ; 

[X,Y,Z] = ndgrid(-m:m,-n:n,-p:p) ; 

x = X(:) ;
y = Y(:) ;
z = Z(:) ; 

r = sqrt(x.^2+y.^2+z.^2) ; 

idx = r <= 10 ; 
plot3(x(idx),y(idx),z(idx),'.r')
axis equal

[Xizeng Feng]

thank you very much! But can we improve it so that the ball looks more pretty?

[KSSV]

How you want to look like? What's your expectations?

[Xizeng Feng]

like this for example.

Answer 3

[J. Alex Lee]

like this? but it doesn't use plot3

[x,y,z] = sphere(64);
p = surf(x,y,z,"FaceColor","interp","EdgeColor","none");
p.CData = rand(size(p.ZData));
colormap gray
axis equal
lighting phong
camorbit(60,0)
axis off