Reshaping a complex 3D array into 1D, and back
94 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Nick Keepfer
le 18 Juin 2020
Réponse apportée : James Tursa
le 18 Juin 2020
I have a 3D complex array of size (nx,ny,nz).
For post-processing purposes I need to convert into a flattened array of size (1,nx*ny*nz)
I then need to convert it back into its 3D form.
The issue here is that the following code destroys the original formatting of the 3D array
1dwave = reshape(3dwave,[nx*ny*nz,1]);
recovered_wave = reshape(1dwave,size(3dwave));
In essence:
1dwave != recovered_wave
Can somebody tell me what the correct way to do this is?
i.e. How can I convert from 3D -> 1D -> 3D whilst preserving shape of the original 3D array
2 commentaires
James Tursa
le 18 Juin 2020
Modifié(e) : James Tursa
le 18 Juin 2020
The reshape( ) function does not change the memory order of the elements. What you have should have worked. Can you give a small example where it doesn't work? Are you sure the original size is strictly 3D with dimensions nx x ny x nz?
Réponse acceptée
James Tursa
le 18 Juin 2020
I suspect the problem may be that you originally put the data into rows of a matrix. This separates the elements in memory. I.e., MATLAB is column ordered for memory layout, and elements of the same column are next to each other in memory. Elements of the same row are not next to each other in memory in general. Once you put the data into rows you have changed the memory layout of the data, and no amount of reshaping will recover the original memory layout of the data. You would have to probably use the permute( ) function to get back to your desired memory layout.
0 commentaires
Plus de réponses (1)
Voir également
Catégories
En savoir plus sur Matrices and Arrays 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!