Selecting a random element from a matrix with a range.

Question

Shane McNamara 2017-10-23

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/362872-selecting-a-random-element-from-a-matrix-with-a-range

评论： Shane McNamara 2017-10-24

I am trying to select a random element from this matrix with a certain range.

 d = rand(10)
 d(end,randperm(size(d,2), 1))

This creates a 10*10 matrix between 1 and 0. I want to slect a random variable < 0.5 but i am trouble applying this to the code. Any help is much appreciated.

2 个评论
显示无隐藏无

Cedric 2017-10-23

There may not be any element < 0.5. How do you define the number of elements that you will pick? What is the purpose?

Shane McNamara 2017-10-24

Thanks for your feedback Cedric. There usually is values above and below .5. I only want to pick one element which is what the above does. I wil apply it in the future to a matrix of zeros and 1's and apply a random movement to the element picked.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Akira Agata 2017-10-24

2
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/362872-selecting-a-random-element-from-a-matrix-with-a-range#answer_287354

在 MATLAB Online 中打开

How about the following script?

d = rand(10);
% Extract elements of d < 0.5
idx = d < 0.5;
d2 = d(idx);
% If d2 is NOT empty, select one element randomly
if ~isempty(d2)
  output = d2(randperm(numel(d2),1));
end