How do I calculate the cross product of two vectors, when the first vector is an element of a N-array and the second vector is an element of an NxD matrix;
2 views (last 30 days)
Show older comments
% The N-array vector initialization:
r1=zeros(i,:); % i: varies from 0 to 360
% The NxD matrix initialization:
r2=zeros(i,j,:); % i: varies from 0 to 360 and j: varies from 10 to 250
% A double for loop is used and it contains the cross product of the
% two:
for i=0:1:360
for j=10:1:250
c=cross(r1(i,:),r2(i,j,:))
end
end
% The error is that Matrices are not of the same size.
0 Comments
Answers (1)
Torsten
on 2 Mar 2024
Moved: Torsten
on 2 Mar 2024
r1 = rand(30,3);
r2 = rand(30,50,3);
for i=1:30
for j=1:50
c(i,j,:)=cross(r1(i,:),squeeze(r2(i,j,:)));
end
end
4 Comments
Paul
on 2 Mar 2024
cross can work on multiple vectors, so a single loop can be used, for whatever that's worth
rng(100)
r1 = rand(30,3);
r2 = rand(30,50,3);
for i=1:30
for j=1:50
c(i,j,:)=cross(r1(i,:),squeeze(r2(i,j,:)));
end
end
for j = 1:50
cc(:,j,:) = cross(r1,squeeze(r2(:,j,:)),2);
end
Or no loop using some extra memory, also for whatever that's worth.
ccc = cross(repmat(reshape(r1,30,1,3),[1 50]),r2);
isequal(c,cc,ccc)
See Also
Categories
Find more on Logical in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!