extract randomly a pair from a list

Question

George 2011-2-21

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1708-extract-randomly-a-pair-from-a-list

Hello , i have this list a=[0,1];b=[1,0];c=[0,-1];d=[-1,0]; list=[a;b;c;d]

I want to extract randomly one of these four pairs and i want to it with a function handle.For example function= @ (i don't know what to put here(i think leaving it empty)) length(list)*rand... Anyway,sth like that. If i call the function it will extract one pair from my list.For example, "0 1".

Thank you.

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

David Young 2011-2-21

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1708-extract-randomly-a-pair-from-a-list#answer_2534

在 MATLAB Online 中打开

Two suggestions. First:

selector1 = @() list(ceil(rand*size(list,1)), :);

Then each time you call

x = selector1()

you will get a random row of list. Note that the list is fixed once selector1 has been constructed: selector1 will always give you rows from the original list, even if you assign a new matrix to the variable "list".

So the second suggestions is:

selector2 = @(list) list(ceil(rand*size(list,1)), :);

which accepts an argument. You get random rows with

x = selector2(list);

This means that you can now get a random row of any matrix, not just the one hard-wired into the selector, and the current value of "list" will be used.

Which one of these you need depends on how you're going to use the function handle.