While loop for testing the end of vector (Matlab)

7 次查看（过去 30 天）

Afluo Raoual 2021-2-17

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/747742-while-loop-for-testing-the-end-of-vector-matlab

评论： Afluo Raoual 2021-2-17

Dear members,

If we have a long vector that we don't know its length, and we want use while loop to repeat the task than stop and exit from the loop when the vector length is at its end.

For example, if the vector length is 10000 bits so we repeat the calculation (of any task) until 10000 than we stop and exit.

But in my case, I don't know the length of my vector. So how can I program this please?

Thank you.

采纳的回答

Rik 2021-2-17

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/747742-while-loop-for-testing-the-end-of-vector-matlab#answer_625547

在 MATLAB Online 中打开

You can use numel to create a loop over a vector of unknown size:

A=rand(1,100);
for n=1:numel(A) % n will go to 100
    %your code here
end

5 个评论
显示 3更早的评论隐藏 3更早的评论

Rik 2021-2-17

You're welcome. If either answer solved your issue, please consider marking it as accepted answer. If you feel both answers solved your issue, pick the best one and give the other an upvote.

If your issue is not yet resolved, feel free to comment with your remaining issues.

Afluo Raoual 2021-2-17

It's done

请先登录，再进行评论。

更多回答（1 个）

Daniel Pollard 2021-2-17

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/747742-while-loop-for-testing-the-end-of-vector-matlab#answer_625542

编辑：Daniel Pollard 2021-2-17

在 MATLAB Online 中打开

If you know that it's 1-dimensional, you can use

numel(vector)

which returns the length of your vector. Also useful to know is

size

which returns the size of a matrix (eg, [2 2] for a 2x2 matrix, [10 1] for a 10x1 vector, etc).

Edit I've replaced length with numel - thank you Rik.

3 个评论
显示 1更早的评论隐藏 1更早的评论

Daniel Pollard 2021-2-17

This is news to me - I've used length multiple times without any issues. What exactly is the bug?

Rik 2021-2-17

The bug is not with length, the bug is with the use of length. For a vector it is equivalent to numel, and for array inputs it is probably not what you mean. How often did you want to loop over max(size(A)) without knowing which dimension is that maximum?

请先登录，再进行评论。

请先登录，再回答此问题。

类别

MATLAB Language Fundamentals Loops and Conditional Statements

在 Help Center 和 File Exchange 中查找有关 Loops and Conditional Statements 的更多信息

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by