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

Question

Yro 2021-5-27

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/841070-how-to-assign-a-given-value-to-an-element-of-an-array-without-repeating-it

评论： Yro 2021-5-27

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.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Walter Roberson 2021-5-27

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/841070-how-to-assign-a-given-value-to-an-element-of-an-array-without-repeating-it#answer_710310

在 MATLAB Online 中打开

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

3 个评论
显示 1更早的评论隐藏 1更早的评论

Walter Roberson 2021-5-27

在 MATLAB Online 中打开

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 2021-5-27