MATLAB Answers

How to generate random matrix from another one?

14 views (last 30 days)
IM
IM on 19 Sep 2019
Commented: IM on 20 Sep 2019
Hi!
I have a 18 x 57x11 matrix .
How can I make a new random matrix (the same size) , which is generated by "shuffling" the values of the original matrix?
A lot thanks in advance!

  1 Comment

Adam Danz
Adam Danz on 19 Sep 2019
Ha! You got 3 different approaches that use randperm() and reshape().
By the way, your data is not a matrix. A matrix is 2 dimensional, with rows and columns. Your data contains a 3rd dimension which makes it an array. All 3 answers will work no matter how many dimensions are in the input.

Sign in to comment.

Accepted Answer

Adam Danz
Adam Danz on 19 Sep 2019
Edited: Adam Danz on 19 Sep 2019
You can use randperm() to shuffle the values of array 'm'.
% Original array
m =rand(180, 57, 11);
% Random permutation index
randpermIdx = randperm(numel(m));
% m shuffled
mShuffle = reshape(m(randpermIdx), size(m));
To convince yourself that mShuffle is merely a random reorganization of m with no additional or missing values or duplicate samples, use this line below which should return True.
isequaln(sort(m(:)),sort(mShuffle(:)))

More Answers (2)

Bruno Luong
Bruno Luong on 19 Sep 2019
A is your input matrix
Ashuffle = reshape(A(randperm(numel(A))),size(A))

Adam
Adam on 19 Sep 2019
newMatrix = reshape( oldMatrix( randperm( numel( oldMatrix ) ) ), size( oldMatrix ) );
should work, though I'm sure there are neater ways.

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by