How do I plot a sphere using the cylinder function?

I know that I can easily plot a sphere using the sphere function, but I am trying to do it with the cylinder function. This is what I have so far, but I can't seem to get the function right.

clc;

x1 = linspace(0,pi,100);

y1 = linspace(0,1,100);

z1 = linspace(0,2,100);

[x2, y2,z2]=cylinder(x.^2+y.^2),200);

figure(2);

surf(x2, y2,z2);

xlabel('X');

ylabel('Y');

zlabel('Z');

colormap(jet)

Answer 1

[Jan]

x = linspace(0, 1, 20);
[X, Y, Z] = cylinder(sqrt(x .* (1 - x)));
surf(X, Y, Z);
axis equal

The first input determines the radius. Then h^2 = p*q helps.

[unknown]

Now this is what I have, but I can't seem to get the Z-axis to be from (-1,1) so that the sphere will look not squashed. Please help.

x = linspace(0, 1, 20);

Z=linspace(-1,1,20);

[X, Y, Z] = cylinder(sqrt(2.*x .* (2 - 2.*x)),20);

figure(2);

surf(X, Y,Z);

xlabel('X');

ylabel('Y');

zlabel('Z');

colormap(jet)

[Jan]

Please use the "{} Code" button to format code. This looks nicer than inserting blank lines.

The line "Z=linspace(-1,1,20);" is useless, because Z is overwritten. Does "Z-axis to be from (-1,1)" mean, that you want a radius of 1? With your code, the Z- axis does not only "look squashed", but the object is not a sphere. Multiplying the radius by 2 deforms it, but as explained in the documentation, the height is still set to 1:

 cylinder treats each element in r as a radius at equally spaced
 heights along the unit height of the cylinder.

Do you want to increase the radius? Then you have to do this with the output of cylinder, not with the input:

x = linspace(0, 1, 20);
[X, Y, Z] = cylinder(sqrt(x .* (1 - x)));
Z = Z - 0.5;
X = X * 2;
Y = Y * 2;
Z = Z * 2;
surf(X, Y, Z);
axis equal

This is a sphere around the origin with radius 1.