data structure for a matrix (2 dimensional) whose elements are a vector

I'd like to encode a m-by-n matrix using matlab.

Problem is each element of the matrix should be a vector of size k.

How to encode this kind of matrix efficiently?

Thanks

Dohoon

Answer 1

[James Tursa]

For memory efficiency, you can use a 3D k-by-m-by-n array A. E.g.,

A(1:k,1,1) = 1st k-vector
A(1:k,2,1) = 2nd k-vector
etc
A(1:k,m,n) = last k-vector

Then each vector's elements would be contiguous in memory and could be extracted with the syntax A(:,x,y) for the "x-y-th" vector.

If you want the syntax to be more natural but give up a little in storage efficiency you can use a cell array. E.g.,

A(1,1) = {1st k-vector}
A(2,1) = {2nd k-vector}
etc
A(m,n) = {last k-vector}

The storage requirements are a bit more than the 3D array, but each vector's elements would still be contiguous in memory and could be extracted with the syntax A{x,y} for the "x-y-th" vector.

[Do-Hoon Kim]

thanks a lot!