copy matched data with multiply\duplicate

amr - There are several ways to do this. If we assume that the first column is in ascending order (will this always be true?), then you can iterate over each row and find those that have the same element in the first row. Try the following

 numCols = 6;
 % initialize the text array
 textArray = cell(size(idx2,1),numCols);
 atRow     = 1; 
 % iterate over each row of idx2
 start = 1;
 for k=2:size(idx2,1)
     % check to see if the kth row is different from the starting row
     if idx2{k,1} ~= idx2{start,1}
         % create the new row
         textArray(atRow,1:numCols) = idx2(start, 1:numCols);
         for r=1:(k - start - 1)
             text(atRow, numCols + r) = idx2(start + r, numCols);
         end
         start = k;
         atRow = atRow + 1;
    end
 end
 % repeat for the final row of idx2
 textArray(atRow,1:numCols) = idx2(start, 1:numCols);
 for r=1:(k - start)
    textArray(atRow, numCols + r) = idx2(start + r, numCols);
 end

Note that text may have several blank rows that you can remove as

textArray(atRow+1:end,:) = [];

Note that text is the name of a built-in MATLAB function so in the above example I renamed it to textArray. (Always try to avoid creating variable with names of MATLAB functions to avoid future headaches when trying to debug the code.)