How to calculate of average numbers every n rows?
39 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Shaochen Hu
le 11 Août 2019
Commenté : Lucas Maes
le 22 Oct 2021
For example I have a 30*10 matrix, I want to calculate a averager number for each column every 3 rows. The result should be a 10*10 matrix.
0 commentaires
Réponse acceptée
John D'Errico
le 11 Août 2019
Modifié(e) : John D'Errico
le 11 Août 2019
Pretty easy. What you need to learn is how MATLAB stores numbers in an array, how to reshape things so that you get what you want.
For example, suppose you reshaped the array to be 3x10x10? Essentially, then each column of the new result will be the three numbers that you want to average. The idea is to bring the numbers you want to associate into ONE column, with each set as one column.
Then you would take the mean of each solumn of that array. The result would be 1x10x10, and we will have averaged the elements together that you wanted averaged.
Getting close. Now all you need do is reshape that result to be 10x10. Or, you could learn to use the squeeze function, and why that function is valuable.
The point is to visualize how the data lives in your array. Then think about how to get where you want to go. So this should work:
B = squeeze(mean(reshape(A,[3,10,10]),1));
4 commentaires
EP
le 22 Sep 2021
Can you take the average and keep the same number of columns? Just set both columns equal to the average?
Plus de réponses (1)
Voir également
Catégories
En savoir plus sur Matrix Indexing dans Help Center et File Exchange
Produits
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!