How to assign a given value to an element of an array without repeating it.

Hello, I need to change the value of an element of the array x for a random value but that this is not repeated in the array. With the following code I check that it is not repeated and then I assign it to the y position.

x = [1 3 5 7 9];
y  = randi([1 10]);
n = randi([1 length(x)]);

if ~ismember(y, x)
    
   disp('  NO')

   x(n) = y;
   
else

But the problem is in the case that it is repeated, how could I re-generate another number and perform the previous procedure.

Thanks in advance.

Answer 1

[Walter Roberson]

x = [1 3 5 7 9]

x = 1×5

1 3 5 7 9

y  = setdiff(randi([1 10]), x)

y = 10

n = randi([1 length(x)])

n = 3

ny = randi([1 length(y)])

ny = 1

x(n) = y(ny)

x = 1×5

1 3 10 7 9

[Yro]

Thank you for your reply,

That works in case the value does not belong to the array. If it does, how can I generate another random value (randi[1 10], for example) and rerun the previous code?

[Walter Roberson]

Correction to the code:

x = [1 3 5 7 9]
y  = setdiff(1:10, x)
n = randi([1 length(x)])
ny = randi([1 length(y)])
x(n) = y(ny)

So y selects the elements of 1:10 that are not in x, and then ny selects a random member of that, so y can never be something that is already in x. No loop is needed.

[Yro]

Thank you very much for your help, the code works.

Best regards.