How to randomly exchange 2 entries in a column?

Question

Grace 2014-10-1

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/156976-how-to-randomly-exchange-2-entries-in-a-column

回答： Star Strider 2014-10-1

Hi, I have

a=[ 1 2;
4;
1;
5;
3]

I want to choose randomly any 2 entries from a column and exchange them. For example, I randomly choose entries 2 and 5 from the second column, exchange these two entries to become

 b=[  1 5;
4;
1;
2;
3]

How am I going to make this? Thanks in advance.

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Answer 1

Star Strider 2014-10-1

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/156976-how-to-randomly-exchange-2-entries-in-a-column#answer_153522

在 MATLAB Online 中打开

This seems to work:

[r,c] = size(a);                    % ‘a’ Row, Col Size
cc = randi(c);                      % Choose Random Column
rc = randi(r, 1, 2);                % Choose Random Rows
b = a;                              % Create ‘b’
b(rc,cc) = a(fliplr(rc), cc)        % Swap Rows of Chosen Column