Plotting Lines and Points in 3D

I need to learn how to plot lines and points in 3D. Can someone please provide an example in Matlab? Thank you.

Answer 1

[Voss]

A = [1 -3  7];
B = [0  2 -6];

C = [0.5 -1 5];

% plot a line from A to B
v = [A; B];
plot3(v(:,1),v(:,2),v(:,3))

box on
grid on
xlabel('x')
ylabel('y')
zlabel('z')

% plot the point C
hold on
plot3(C(1),C(2),C(3),'o')

[DJ V]

Thank you for troubling to answer: I come up with the following trying to create a drawing, but two of the lines aren't being shown. The ones that go to -1 on the Y axis. Can this be fixed to include the -1 on the Y axis? Is there a way to control the magnitude of the box that is being turned on? Is there a way to control the dimensions of the box that is turned on? Thanks.

A1 = [0 0 0];
A2 = [1 1 2];
A3 = [-1 1 2];
A4 = [1 -1 2];
A5 = [-1 -1 2];
% plot a line from A1 to AN
v = [A1; A2];
plot3(v(:,1),v(:,2),v(:,3))
box on
hold on
v = [A1; A3];
plot3(v(:,1),v(:,2),v(:,3))
hold on
v = [A1, A4];
plot3(v(:,1),v(:,2),v(:,3))
hold on
v = [A1, A5];
plot3(v(:,1),v(:,2),v(:,3))
hold on
box on
grid on    

[Voss]

You're welcome!

The problem with the plots involving A4 and A5 is that you're horizontally concatenating instead of vertically concatenating, which makes v 1x6 instead of 2x3. When v is 1x6, doing plot3(v(:,1),v(:,2),v(:,3)) plots a single point instead of two points with a line in between.

A1 = [0 0 0];
A2 = [1 1 2];
A3 = [-1 1 2];
A4 = [1 -1 2];
A5 = [-1 -1 2];

% plot a line from A1 to AN
v = [A1; A2];
plot3(v(:,1),v(:,2),v(:,3))
hold on

v = [A1; A3];
plot3(v(:,1),v(:,2),v(:,3))

v = [A1; A4];
%      ^ semicolon (not comma)
plot3(v(:,1),v(:,2),v(:,3))

v = [A1; A5];
%      ^ semicolon (not comma)
plot3(v(:,1),v(:,2),v(:,3))

box on
grid on

You can control the axes limits (and thus the box around the axes) using xlim, ylim, and zlim, e.g.:

ylim([-1 2])

[DJ V]

Thank you very much!

[Voss]

You're welcome! Any questions, let me know. Otherwise, please "Accept" this answer. Thanks!

[DJ V]

Is there any command I can give to get MATLAB to draw this thing to scale? Thank you.

[Voss]

axis equal

[DJ V]

The man with all the answers!

[Voss]

https://youtu.be/S9RVS8cjNN0?feature=shared