How do i select random indicies from an array?
1 vue (au cours des 30 derniers jours)
Afficher commentaires plus anciens
ME
le 5 Mar 2015
Réponse apportée : Image Analyst
le 5 Mar 2015
I have an array of 10 by 6. is there a way I can randomly select rows from this particular array and everything within it.
0 commentaires
Réponse acceptée
Image Analyst
le 5 Mar 2015
Let's say you have a 10-by-6 matrix m, and you want to select 7 rows at random and make sure there are no repeats. Do this:
m = randi(9, 10,6)
randomRows = randperm(size(m, 1), 7)
randomRows is the array of row numbers , not the actual 6 element rows themselves.
0 commentaires
Plus de réponses (1)
Joseph Cheng
le 5 Mar 2015
Modifié(e) : Joseph Cheng
le 5 Mar 2015
yes, you can perform something like this. Lets say your 10 by 6 array is called A;
then to get the random row(s) you can do
A(randi(10,N,1),:)
where 10 is the number or rows in A (or you can do size(A,1) if you do not want to hard code 10), N is the number of random rows you want to select and the : selects all columns.
2 commentaires
Image Analyst
le 5 Mar 2015
Just a watchout: With randi(), it's really random meaning that there is a possibility that the same row might be "chosen" twice or more. If you don't want that (you want, say, 5 rows and all rows to be unique), then use randperm() instead.
Voir également
Catégories
En savoir plus sur Creating and Concatenating Matrices 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!