Extracting a matrix by row and column from a large matrix

Question

Tanmoyee Bhattacharya 2019-5-21

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/463335-extracting-a-matrix-by-row-and-column-from-a-large-matrix

评论： Adam Danz 2019-5-21

I have a matrix like

1 1    2000
1 1    2000
1 1    2000
2 2    3000
2 2    3000
2 2    3000
3 3    5000
3 3    5000
3 3    5000

I have another matrix

2 2    
2 2    
2 2    

I want a matrix from this matrix large matrix given above

2 2   3000
2 2   3000
2 2   3000

Can anyone help to extract the values through matlab.I am trying throuh ismember but not working.

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Bob Thompson 2019-5-21

What kind of conditions are you hoping to meet, or do you literally just want any row which contains [2 2 2 3000]?

Adam Danz 2019-5-21

在 MATLAB Online 中打开

Tanmoyee Bhattacharya answer moved here

I have another matrix

2 2
2 2
2 2

I have to extract the 4,5,6 row and four column from the large matrix by the given matrix

2 2   3000
2 2   3000
2 2   3000

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Answer 1

Adam Danz 2019-5-21

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https://ww2.mathworks.cn/matlabcentral/answers/463335-extracting-a-matrix-by-row-and-column-from-a-large-matrix#answer_376051

编辑：Adam Danz 2019-5-21

在 MATLAB Online 中打开

I changed your example matrix a bit to make sure it ignores partial pattern matches.

m = [1 1 1    2000
1 1    2000
1 1    2000
2 2    3000
2 2    3000
2 2    3000
3 3    5000
3 3    5000
3 3    5000
2 2    6000
2 2    6000
9 9    7000];
s = [2 2 2
2 2
2 2];
[~, rowIdx] = intersect(m,s); 
mSubset = m(rowIdx+(0:size(s,1)-1),:); 

Result

mSubset =
           2           2           2        3000
           2           2           2        3000
           2           2           2        3000

Note that if there is more than 1 match it will only return the first subset match.