hemisphere

Create hemisphere

Adaption of the default Matlab sphere function to create hemispheres.

Syntax

[X,Y,Z] = hemisphere

[X,Y,Z] = hemisphere(n)

hemisphere(___)

hemisphere(ax,___)

Description

[X,Y,Z] = hemisphere returns the x-, y-, and z- coordinates of a hemisphere without drawing it. The returned hemisphere has a radius equal to 1 and consists of 20-by-20 faces.

The function returns the x-, y-, and z- coordinates as three 21-by-21 matrices.

To draw the hemisphere using the returned coordinates, use the surf or mesh functions.

[X,Y,Z] = hemisphere(n) returns the x-, y-, and z- coordinates of a hemisphere with a radius equal to 1 and n-by-n faces. The function returns the x-, y-, and z- coordinates as three (n+1)-by-(n+1) matrices.

hemisphere(___) plots the hemisphere without returning the coordinates. Use this syntax with any of the input arguments in previous syntaxes.

hemisphere(ax,___) plots into the axes specified by ax instead of the current axes. Specify the axes as the first input argument.

Examples

Display Unit Hemisphere

hemisphere
axis equal

Specify Hemisphere Radius and Location

Specify the radius and location of a hemisphere by modifying the returned X, Y, and Z coordinates.

Define X, Y, and Z as coordinates of a unit hemisphere.

[X,Y,Z] = hemisphere;

Plot the unit hemisphere centered at the origin.

surf(X,Y,Z)
axis equal

Define X2, Y2, and Z2 as coordinates of a hemisphere with a radius of 5 by multiplying the coordinates of the unit hemisphere. Plot the second hemisphere, centering it at (5,-5,0).

hold on
r = 5;
X2 = X * r;
Y2 = Y * r;
Z2 = Z * r;

surf(X2+5,Y2-5,Z2)

Display Sphere with Different Numbers of Faces

Call the tiledlayout function to create a 2-by-2 tiled chart layout. Call the nexttile function to create the axes. Then, use the hemisphere function to plot three hemispheres with different numbers of faces into different tiles of the chart by specifying the axes.

tiledlayout(2,2);
ax1 = nexttile;
hemisphere(ax1);
axis equal
title('20-by-20 faces (Default)')

ax2 = nexttile;
hemisphere(ax2,50)
axis equal
title('50-by-50 faces')

ax3 = nexttile;
hemisphere(ax3,100)
axis equal
title('100-by-100 faces')

Create Hemispherical Cylinder

Combine hemisphere with cylinder to create a hemispherical cylinder or cylinder with rounded ends.

Plot the cylinder.

[X1,Y1,Z1] = cylinder;
surf(X1,Y1,Z1); % plot cylinder
axis equal

Add the top and bottom hemispherical ends.

[X2,Y2,Z2] = hemisphere;
hold on
surf(X2,Y2,Z2+1); % plot top hemisphere
surf(X2,Y2,-Z2); % plot bottom hemisphere

See Also

hemicylinder