How can I extract specific columns of a Matrix

Question

ghazale 2013-10-29

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/104275-how-can-i-extract-specific-columns-of-a-matrix

编辑： Cedric 2013-10-29

For example I have this matrix

A = [1 0 0 0;0 0 0 0;0 1 0 0;0 0 0 0]

I want just extract the columns that they have one, (in this matrix will be column 1 and 2), and then show it in another matrix. I want to do this function for a big matrix. so the question must be d = [1 0;0 0;0 1;0 0]

Thanks

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Answer 1

Cedric 2013-10-29

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/104275-how-can-i-extract-specific-columns-of-a-matrix#answer_113605

编辑：Cedric 2013-10-29

在 MATLAB Online 中打开

Here is an example

 >> A = [1 0 0 0;0 0 0 0;0 1 0 0;0 0 0 0]
 A =
     1     0     0     0
     0     0     0     0
     0     1     0     0
     0     0     0     0
 >> colId = any(A, 1)
 colId =
     1     1     0     0
 >> d = A(:,colId)
 d =
     1     0
     0     0
     0     1
     0     0