15.2.2.3 Three-dimensional Geometric Shapes

Command: cylinder

Function File: cylinder (r)

Function File: cylinder (r, n)

Function File: cylinder (hax, …)

Function File: [x, y, z] = cylinder (…)

Plot a 3-D unit cylinder.

The optional input r is a vector specifying the radius along the unit z-axis. The default is [1 1] indicating radius 1 at Z == 0 and at Z == 1.

The optional input n determines the number of faces around the circumference of the cylinder. The default value is 20.

If the first argument hax is an axes handle, then plot into this axis, rather than the current axes returned by gca.

If outputs are requested cylinder returns three matrices in meshgrid format, such that surf (x, y, z) generates a unit cylinder.

Example:

[x, y, z] = cylinder (10:-1:0, 50);
surf (x, y, z);
title ("a cone");

See also: ellipsoid, rectangle, sphere.

Function File: sphere ()

Function File: sphere (n)

Function File: sphere (hax, …)

Function File: [x, y, z] = sphere (…)

Plot a 3-D unit sphere.

The optional input n determines the number of faces around the circumference of the sphere. The default value is 20.

If the first argument hax is an axes handle, then plot into this axis, rather than the current axes returned by gca.

If outputs are requested sphere returns three matrices in meshgrid format such that surf (x, y, z) generates a unit sphere.

Example:

[x, y, z] = sphere (40);
surf (3*x, 3*y, 3*z);
axis equal;
title ("sphere of radius 3");

See also: cylinder, ellipsoid, rectangle.

Function File: ellipsoid (xc, yc, zc, xr, yr, zr, n)

Function File: ellipsoid (…, n)

Function File: ellipsoid (hax, …)

Function File: [x, y, z] = ellipsoid (…)

Plot a 3-D ellipsoid.

The inputs xc, yc, zc specify the center of the ellipsoid. The inputs xr, yr, zr specify the semi-major axis lengths.

The optional input n determines the number of faces around the circumference of the cylinder. The default value is 20.

If the first argument hax is an axes handle, then plot into this axis, rather than the current axes returned by gca.

If outputs are requested ellipsoid returns three matrices in meshgrid format, such that surf (x, y, z) generates the ellipsoid.

See also: cylinder, rectangle, sphere.