Angles between 3 vector in 3d

2014 2 5
2 个回答
回答已采纳
更新时间：2014 2 5
7 次查看（30 天）

0 个投票

Hi I am trying to find angle between 3 vectors;
Terminal vector:-0.063695 -0.588189 2.333766
1. vector: 0.008239 -0.640457 2.295980 2.vector: -0.024011 -0.216596 2.461521
Could anyone help me?
Thanks in advance

请先登录，再回答此问题。

 采纳的回答

Mischa Kim
Mischa Kim 2014-2-5

1 个投票

You can make use of the dot product (between vectors):
vec1 = [-0.063695 -0.588189 2.333766];
vec2 = [0.008239 -0.640457 2.295980];
angle_12 = acos(dot(vec1,vec2)/(norm(vec1)*norm(vec2)))
and similar for the other pairs of vectors.

3 个评论
显示 1更早的评论 隐藏 1更早的评论

barbar
barbar 2014-2-5
Thank you for your response but I ve already tried that command. Actually I misrepresented my problem.
Right know I have three positions and each one is in the 3d space. The origin of these positions is terminal position. So I want to find the angle between these positions which is created by first and second positions on terminal position. Sorry about my poor writing skills but I hope I express myself clearly. Thanks again
Mischa Kim
Mischa Kim 2014-2-5
I see...
vec = [-0.063695 -0.588189 2.333766];
vec1 = [0.008239 -0.640457 2.295980];
vec2 = [-0.024011 -0.216596 2.461521];
dv1 = vec1 - vec;
dv2 = vec2 - vec;
angle_12 = acos(dot(dv1,dv2)/(norm(dv1)*norm(dv2)))
barbar
barbar 2014-2-5
Thank you.I guess displacement calc. should work for my situation.

请先登录，再进行评论。

更多回答（1 个）

Roger Stafford
Roger Stafford 2014-2-5

0 个投票

The 'atan2' function is more accurate than 'acos' for vectors that are nearly parallel. For two 3D vectors v1 and v2, do this:
ang = atan2(norm(cross(v1,v2)),dot(v1,v2));
This angle will be in radians.

类别

在 帮助中心 和 File Exchange 中查找有关 Develop Apps Using App Designer 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by