3-D Visualization

Line Plots of 3-D Data

The 3-D analog of the plot function is plot3. If x, y, and z are three vectors of the same length,

plot3(x,y,z)

generates a line in 3-D through the points whose coordinates are the elements of x, y, and z and then produces a 2-D projection of that line on the screen. For example, these statements produce a helix.

t = 0:pi/50:10*pi;
plot3(sin(t),cos(t),t)
axis square; grid on

Plotting Matrix Data

If the arguments to plot3 are matrices of the same size, MATLAB plots lines obtained from the columns of X, Y, and Z. For example,

[X,Y] = meshgrid([-2:0.1:2]);
Z = X.*exp(-X.^2-Y.^2);
plot3(X,Y,Z)
grid on

Notice how MATLAB cycles through line colors.

A Typical 3-D Graph

Representing a Matrix As a Surface