How do I simplify this code (remove for loop)?

1 次查看（过去 30 天）
Josh
Josh 2011-6-21
I'm trying to get in the habit of writing my code in terms of matrix operations and using as few for loops as possible. Is there a better way to write this code without the for loop?
for ii=1:N
if (acos(dot(rel_vec,vec_array(:,ii))) > pi/2)
vec_array(:,ii) = -vec_array(:,ii);
end
end
vec_array is matrix containing N vectors (3xN). I compare each vector in the matrix to make sure they're within 180 degrees of some relative vector (rel_vec). If the vector is more than 180 degrees away, I multiply the vector by -1.

请先登录，再回答此问题。

采纳的回答

Oleg Komarov
Oleg Komarov 2011-6-21
idx = acos(rel_vec * vec_array) > pi/2;
rvec(:,idx) = -rvec(:,idx);
where rel_vec is 1 by 3.

更多回答（1 个）

Josh
Josh 2011-6-21
Yah, that'll do it. I knew there was a much easier way to do it. Thanks!

类别

在 Help Center 和 File Exchange 中查找有关 Creating and Concatenating Matrices 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