shuffling elements between two matrices

Hi all,

I have two signals meg1 and meg2: [3 x 1801 x 53] and [3 x 1801 x 60] type meeg. I can easily split them into three arrays of : 1 x 1801 x 53 type double. But what I need to do is to make both meg signals as random as possible so preferebly shuffle the elements between them two like n times. I tried to do it just within each matrix with function randswap http://www.mathworks.co.uk/matlabcentral/fileexchange/12621-randswap but it gives an error for elements type double. Has anyone got any idea how to do it? Would be veeeery grateful!!

Many thanks in advance, Lidia

Answer 1

[Image Analyst]

What do you mean "between them"? They're different sizes in the 3rd dimension.

Here, use randperm(). Try this:

m = magic(5) % Sample data
% Get random indexes to pull the new values from.
randomIndexes = randperm(numel(m));
% Assign random locations to new matrix
mNew = reshape(m(randomIndexes), size(m))

[Lidia]

Hi, They are different sizes but they don't need to exchange all the elements. Yeah it worked. Thank you so much! So m(randomIndexes) transforms 'm' to a vector?

[Image Analyst]

Yes. That's "linear indexing" - it gives a 1D vector. So that's why I had to call reshape() - to get it back into the original shape.