Alternation without for loop

1 view (last 30 days)
JamJan
JamJan on 15 Oct 2019
Commented: J. Alex Lee on 15 Oct 2019
I have 2 vectors that I want to alternate
A = [1 2 3 4 5 6 7 8 9 10]
B = [0.5 0.2 0.4 0.8 0.9]
I would like to have the following output (preferably without for loop)
Output = [1 0.5 2 0.2 3 0.4 4 0.8 5 0.9 6 7 8 9 10]
How to do this?
Thanks!

Answers (3)

Stephen23
Stephen23 on 15 Oct 2019
Edited: Stephen23 on 15 Oct 2019
>> N = min(numel(A),numel(B));
>> V = [reshape([A(1:N);B(1:N)],1,[]),A(N+1:end),B(N+1:end)]
V =
1 0.5 2 0.2 3 0.4 4 0.8 5 0.9 6 7 8 9 10
  1 Comment
J. Alex Lee
J. Alex Lee on 15 Oct 2019
nice...i like when i didn't see the obvious complete opposite path...and i learned a new thing with the empty argument for reshape

Sign in to comment.


Jos (10584)
Jos (10584) on 15 Oct 2019
% a sorting trick
A = [1 2 3 4 5 6 7 8 9 10]
B = [0.5 0.2 0.4 0.8 0.9]
C = [A B] ;
[~,ix] = sort([1:numel(A) 1:numel(B)])
C = C(ix)

J. Alex Lee
J. Alex Lee on 15 Oct 2019
Here's a possibility: if A and B were guaranteed to be the same length (your example is not) and row vectors, you could do
N = length(A)
Output = reshape([A(:),B(:)]',2*N,1)
If not same length, you can nan-pad the shorter vector and remove later.

Categories

Find more on Loops and Conditional Statements 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!