Could anyone help me how to extract different specific number of rows in a matrix.

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jaah navi 2021-6-25

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评论： Walter Roberson 2021-6-25

I am a matrix of size A= rand(100,1)

I want to generate matrix by extracting 2 rows in interval of 5.

B=A([1:2,6:7,11:12,16:17,........,96:97],:).

Could anyone help me to write in the simplified form to execute in matlab.

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Walter Roberson 2021-6-25

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在 MATLAB Online 中打开

row_idx = reshape((1:5:100) + [0;1],1,[])
row_idx = 1×40
     1     2     6     7    11    12    16    17    21    22    26    27    31    32    36    37    41    42    46    47    51    52    56    57    61    62    66    67    71    72

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Walter Roberson 2021-6-25

在 MATLAB Online 中打开

?? row_idx is already a separate matrix. You take it and

B = A(row_idx,:);

Walter Roberson 2021-6-25

在 MATLAB Online 中打开

For 2, 3, 4 of each group of 5,

row_idx = reshape((1:5:100) + [1;2;3],1,[])

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Scott MacKenzie 2021-6-25

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在 MATLAB Online 中打开

B = A(sort([1:5:100 2:5:100]))

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jaah navi 2021-6-25

Thanks for your help.

jaah navi 2021-6-25

If suppose instead of two rows I need to have value of 2,3,4 in each intervals of 5. In that case the above command doesnt executes. could you help me on this.

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