How do I create a function that takes a vector of arbitrary length as an input argument and randomly permutes it as an output argument using the identity matrix, without using the randperm command?

function [ x ] = myPerm(A)
    A = ()
    myLength = length(A)
    I = eye(length(A))
end

this is what I have, I need help creating the arbitrary length and permuting the matrix

[Walter Roberson]

Is it permitted to use rand or randi ? What is the reason that randperm cannot be used ? For example if it has to do with code generation then say so in order that we do not suggest other possibility with the same restrictions .

[shay kent]

yes, randperm cannot be used because of code generation. rand and randi can be used. The idea is to ceate a code that permutates a matrix without using the the randperm shortcut in matlab

[Walter Roberson]

you have not put in any version information and full code generation is currently supported for randperm .

If permutation of aa vector is needed then why bother with an identity matrix ?

Sorry but this is sounding like a homework assignment not a real task.

[KSSV]

How about using randsample?

Answer 1

[Stephen23]

For an array of any size:

>> M = reshape(1:12,3,4)
M =
    1    4    7   10
    2    5    8   11
    3    6    9   12
>> [~,X] = sort(rand(1,numel(M)));
>> M(:) = M(X)
M =
    8    9    2    7
    5    4   11    1
    3    6   12   10

Answer 2

[Bruno Luong]

Fisher–Yates shuffle

for i = length(A):-1:2
    j = ceil(i*rand);
    A([i,j]) = A([j i]);
end