Grouping matched data by row and column

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I have a matrix attached, Rows_col.mat. This gives the Row and column of some other matrix that has matched a condition I have imposed. So for example, 6 has matched with 1, 19 has matched with 7. However there are occasions where there are more matches, for example 9 has matched with 3, but 17 has also matched with 3. In this instance I would like the output to be [9, 17, 3] (the order is not important). I think the output in a cell array would be the most suitable since there is a varying matrix column size for each "match". I hope this is clear, This for example would be the desired output:
[6,1];[9,3,17 (any order would be fine)];[19,7];[15,10,23];[12,11,18];[21,13];[20,14], this would be a 7x1 cell.
Thankyou.
  3 Comments
Matlab User
Matlab User on 23 Mar 2016
I'm not sure that my explanation was good enough. I would like, for example you see in my matrix that there is a [9, 3] pair and also a [17, 3]. They both share a common value, 3, so I would like to concatenate the elements, so now [9,3,17] are all in one. When it comes to the order, I meant that it would be fine to have [3 9 17],[9 ,3,17 ],[17,3,9]...ETC, so long as all three (in this case) elements are there.

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Accepted Answer

Guillaume
Guillaume on 23 Mar 2016
Edited: Guillaume on 23 Mar 2016
I don't think that there is any other way than using loops to solve this. This works:
Rows_col_ = [6 1; 9 3; 17 3; 19 7; 17 9; 15 10; 23 10; 12 11; 18 11; 18 12; 21 13; 20 14; 23 15];
sequences = {};
for row = Rows_col_' %iterate over the rows of Rows_Cols
hascommonvalue = cellfun(@(s) any(ismember(row, s)), sequences); %check if current row has any value common to a stored sequence
if any(hascommonvalue)
%current row has a common value with one or more sequence already stored, group all together
newmatch = unique([sequences{hascommonvalue}, row']); %concatenate all matching sequences and current row
sequences(hascommonvalue) = []; %remove matching sequences since they've been concatenated as a new sequence
sequences{end+1} = newmatch; %and add new sequence
else
%current did not match any previous sequence, add as new
sequences{end+1} = row';
end
end
  1 Comment
Matlab User
Matlab User on 24 Mar 2016
Thankyou, I was trying to avoid loops but this works very well so thanks again.

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