How can I index a vector based on the vector's values?
5 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Shahriyar Karim
le 13 Mar 2020
Commenté : Shahriyar Karim
le 13 Mar 2020
Say I have a vector,
V = [2 5 4 1 3]
and I want to use the numbers of the vector itself to index. Starting from 1, I go to the first element in V; which = 2.
From there, I want to go to the 2nd element of V--5, then 3, then 4, and finally 1.
How would I go about extracting Vnew = [1 2 4 5 3]?
So far I've tried:
V(V) = [5 3 1 2 4]
I'm assuming it'll require some sort of loop but I'm completely stumped right now.
EDIT: Apologies for the confusion in the explanation above; I don't need the produced vector, but the order in which it's produced--if that makes any sense.
Starting at index 1 of V, I get 2. Then I use 2 as the index of V to get 5--use 5 to get 3--3 for 4---4 loops back to 1.
The part I need is the order in which I loop through. The first index will always be 1, but say the first element of V was 3. I'd then go to the THIRD element of V and Vnew for the third element would equal 2. Using this method, I need to output Vnew = [1 2 4 5 3].
3 commentaires
Réponse acceptée
Plus de réponses (1)
Fangjun Jiang
le 13 Mar 2020
I believe it is like this
V = [2 5 4 1 3];
newV=zeros(size(V));
index=1;
for k=1:numel(V)
newV(k)=V(index)
index=newV(k);
end
2 commentaires
Fangjun Jiang
le 13 Mar 2020
I don't get it. Your expected Vnew is wrong according to your explaination.
Voir également
Catégories
En savoir plus sur Matrix Indexing dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!