Swap 3 random elements in an array

How do I randomly swap three elements in an array? The element at selected position one will be moved to selected position two, the previous element at selected position two will be moved to position three, and the element at position three will be moved to selected position one.
For example: a=[4 2 3 1 5 7 6] would become anew=[4 2 6 1 3 7 5]
Thank you

 Respuesta aceptada

Steven Lord
Steven Lord el 20 de Ag. de 2018
Use randperm to select 3 elements (without replacement) from your vector.
a = [4 2 3 1 5 7 6]
ind = randperm(numel(a), 3)
a(ind) = a(ind([3 1 2]))

Más respuestas (1)

KALYAN ACHARJYA
KALYAN ACHARJYA el 20 de Ag. de 2018
Editada: KALYAN ACHARJYA el 20 de Ag. de 2018
% I have tried this only swap two elements or even numbers, definite swap with each other is only possible in even numbers.
a=randperm(7)
idx=randperm(3);
a(idx)=a(fliplr(idx))
I have tried in another way, you can do that
a=randperm(7)
n=randi(5);
new_array=a(:,:);
new_array([n n+1 n+2])=a([n+2 n n+1])

4 comentarios

Amine Ne
Amine Ne el 20 de Ag. de 2018
Thank you KALYAN, It does not work for example a = [6 7 1 5 2 3 4] becomes [6 7 1 4 2 7 4].
KALYAN ACHARJYA
KALYAN ACHARJYA el 20 de Ag. de 2018
Wait I am doing, there is little an issue.
KALYAN ACHARJYA
KALYAN ACHARJYA el 20 de Ag. de 2018
I have added (Edited answer) another way, pls try, if OK pls confirm it
Amine Ne
Amine Ne el 20 de Ag. de 2018
Editada: Amine Ne el 20 de Ag. de 2018
The second solution allows to swap between 3 consecutive elements.
For example: a=randperm(7)=[7 5 4 1 2 3 6];
n=randi(5)=4; new_array=a(:,:);
new_array([n n+1 n+2])=a([n+2 n n+1])=[7 5 4 3 1 2 6]
I think it is good for me, Thank you KALYAN ACHARJYA for your help and your time.

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