Extract columns in a loop

Question

Francis Herman 2017-9-19

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回答： Walter Roberson 2017-9-19

Hello, I am trying to extract every 2000 rows in a 20000 row column and place each extracted matrix into a separate column to create a 2000x10 matrix. However, I am getting an error: In an assignment A(:) = B, the number of elements in A and B must be the same. Any ideas?

   Test=zeros(2000,10);
      for w=1:10
      Test(w)=zt3((2000.*(w-1))+1:2000.*w,1:1)
      end

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Answer 1

OCDER 2017-9-19

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编辑：OCDER 2017-9-19

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Is this what you want to do?

 zt3 = [1:20000]'; %assuming zt3 is a 20000x1 matrix
 Test = reshape(zt3, 2000, 10);
 %Takes row 1:2000, 2001:4000, etc and stores each in a column in a new matrix.

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Francis Herman 2017-9-19

Yes, this solved my problem. Thank you very much for the help.

OCDER 2017-9-19

在 MATLAB Online 中打开

You're welcome! Oh, I should have explained why your code didn't work. You were doing Test(w) = zt3(1:2000), but Test(w) is 1 element while zt3(1:2000) is 2000 elements. The elements must match in input and output. To make the for loop work, you'd have to fix it as below:

   Test = zeros(2000, 10);
   for w = 1:10
     Test(:, w) = zt3(2000*(w-1)+1:2000*w, 1); 
     %Fill all row " : " for column number w in Test
   end