MATLAB Answers

Question about concatenation in for-loop

27 views (last 30 days)
Hello,
I am trying to concatenate a 2D matrix into a 3D matrix where the length of the 3rd dimension is dependent on length of a vector previously asigned. For example, given
A = [1,2,3,4,5];
B = [1,2;3,4];
I would like creat marix C with size 2x2x5. I can do this easily by doing
C = cat(3,B,B,B,B,B);
However if I change the length of A, I want to write my code so that I don't have to update then number of times "B" repeats itself inside the cat function. I tried using the folowing for-loop but it didn't work. Any advice would be appreciated.
for i=1:length(A)
C = cat(3,B,B)
end

  1 Comment

Patrick Keiffer
Patrick Keiffer on 9 Jan 2019
So I figured it out. The folowing code works.
A = [1,2,3,4,5];
B = [1,2;3,4];
C = B;
for i=1:length(A)
C = cat(3,C,B);
end

Sign in to comment.

Accepted Answer

OCDER
OCDER on 9 Jan 2019
Instead of cat, use repmat for your case, as you're repeatedly stacking a matrix in a dimension.
B = rand(2, 5)
C = repmat(B, 1, 1, 5) %stacks B in the 3rd dimension 5 times

  1 Comment

Patrick Keiffer
Patrick Keiffer on 9 Jan 2019
Oh, thats a great solution. Thanks!

Sign in to comment.

More Answers (0)

Products


Release

R2017b

Community Treasure Hunt

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

Start Hunting!

Translated by