Matrix rows and columns swapping
131 views (last 30 days)
Show older comments
I want to completely change rows and column simultaneously (please see the picture attached)
Is there a function which can do this?
Thanks,
Rakesh
2 Comments
Logan Hall
on 24 Feb 2021
For anyone who is looking to swap an array:
Array = Array.';
btw sorry for reviving a dead thread.
Walter Roberson
on 24 Feb 2021
That does not solve the user's problem at all. The user needs the upper left corner (a 1 in their data) to go to the middle, but using .' would leave the upper left corner exactly where it is.
Answers (3)
Walter Roberson
on 11 Nov 2019
There is no function that can do that simultaneously, at least not the first time.
For any given row and column exchange pattern, it is possible to pre-process the pattern so that doing the same exchange for multiple different arrays would take place simultaneously for that one matrix. Something like
temp = preprocess_exchange(rows_to_exchange, columns_to_exchange);
newA = A(temp);
newB = B(temp);
where preprocess_exchange is a function that would need to be written.
2 Comments
Walter Roberson
on 12 Nov 2019
I should correct myself: you can do this with indexing.
>> A = [1 2 3;4 5 6;7 8 9]
A =
1 2 3
4 5 6
7 8 9
>> A([2 1 3],[2 1 3])
ans =
5 4 6
2 1 3
8 7 9
Akira Agata
on 12 Nov 2019
I don't think rows and column can be randomly changed simultaneously.
There should be at least 2 steps, like this:
% Input 3-by-3 matrix
A = reshape(1:9,3,3)';
% Randomize rows and columns
A = A(randperm(3),:);
A = A(:,randperm(3));
Franco Garcia
on 24 Feb 2022
Edited: Franco Garcia
on 24 Feb 2022
You can actually do that easily with just proper indexing. According to the example in the attachment:
A=[1,2,3;4,5,6;7,8,9] % The input in your example
B=A([2,1,3],[2,1,3]) % Your expected output
Regards!
1 Comment
Walter Roberson
on 24 Feb 2022
I gave the indexing solution at https://www.mathworks.com/matlabcentral/answers/490529-matrix-rows-and-columns-swapping#comment_766334
See Also
Categories
Find more on Matrices and Arrays in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!