MATLAB Answers

1

plotting normal vector in 3d

Asked by Jack_111 on 30 Jul 2013
I have three points P0=[x0,y0,z0], P1=[x1,y1,z1] P2=[x2,y2,z2] and I want to calculate the normal out of them what I did is
normal = cross(P0-P1, P0-P2);
and then I wanted to plot the normal so what I did is,
c = normal + P0 %end position of normal vector
quiver3(P0(1), P0(2), P0(3), c(1), c(2), c(3)); but it didn't work any suggestions please
%......Edited

  0 Comments

Sign in to comment.

1 Answer

Answer by Matt Kindig on 30 Jul 2013
 Accepted Answer

doc quiver3

  11 Comments

The answer is larger than -8.278e-25
Then what I said above is correct. Your dot product is as close to zero as you'll be able to calculate. In other words, your calculated vector (from the cross product) is as close to normal to the plane as you'll be able to get.
I'm not really sure what else to say. Your code is correct, your answer is correct, and that's that. Read http://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html for why exact floating-point calculations are not possible with a computer.
Thank you for your support

Sign in to comment.