Reduce Matrix Dimensions for 5D-Data

Lets say we have a 5D-Matrix M and want to convert it to 4D-matrix M' in a way such that we combine dim1 and dim3 into a new dim1':

Or more mathematically (hopefully this notation is understandable):

M'(:,m,n,p) = M(:,m,:,n,p) for all m,n,p.

Obviously we could use loops for that, but im looking for a more elegant way, maybe we could make clever use of sub2ind?

[Mara]

Hey Matthias,

maybe the function reshape() might help you with that

[Matthias Saurer]

You were absoluteley rigth, and permute was the last piece of the puzzle. Thanks for your help, Mara

Answer 1

[Srivardhan Gadila]

You can make use of the functions permute and reshape as follows:

% M is a matrix of size a x b x c x d x e
Mp = permute(M,[1 3 2 4 5]);
Md = reshape(Mp,[],b,d,e);

[Matthias Saurer]

Nice and simple, thank you Sir!