plotting normal vector in 3d

29 次查看（过去 30 天）

Jack_111 2013-7-30

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/83543-plotting-normal-vector-in-3d

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

采纳的回答

Matt Kindig 2013-7-30

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/83543-plotting-normal-vector-in-3d#answer_93116

doc quiver3

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.

Jack_111 2013-8-1