how to get common elements within a cell array?

hey all

If i have following array:

   {[1,7];[2,6,1];[7,1,3];[3,5]}

how can I compare each cell in this array with all other cells'values. for example for first cell [1,7] i have to compare it with all other cells and find common values. to compare with [2,6,1] we will get 1, to compare with [7,1,3] we will get [1,7] and with [3,5] we will get an empty cell. Similarly after this we will compare 2nd cell [2,6,1] with all cells in array.

please help

[Jan]

What is the wanted output for this example?

[Tha saliem]

Actually i want intersection of the results of all comparisons for one cell. Like comparison of cell 1 gives

    comparisonResult{1} = {[1],[1,7],[]}
and final result for cell 1 is:
    finalResult{1} ={[1,7]} (if either 1 or 7 exists more than 1 time in comparisonResult, we will write it once).

Similarly for cell 2:

    comparisonResult{2} = {[1],[1],[]}
    FinalResult{2}={1}

[Greg]

Did you try intersect? Probably need a loop or cellfun to go with it.

[Jan]

Do the single vectors have unique elements? In other words: Is this possible as input or not:

{[1,7]; [2,6,1,1,6]}

[Tha saliem]

Yes they have unique elements.. [2,6,1,1,6] is not possible

Answer 1

[the cyclist]

Do you need the comparison result? If not, I think this skips right to the final result

aL =  1:length(a);
for na = aL
  finalResult{na} = intersect([a{na}],[a{setdiff(aL,na)}]);
end

This code is a bit obfuscated. But if it gives the result you expect, I can try to help you understand it if you need me to.

[Tha saliem]

Thanks alot for your time. yes it gives desired results. I am trying to understand it. confused about this part code [a{setdiff(aL,na)}].

and what can i do to achieve comparison result too?

[the cyclist]

Here is the de-obfuscated version of my code, commenting on what each piece does.

% The data
a = {[1,7];[2,6,1];[7,1,3];[3,5]};

% Vector from 1 to the length of a
aL =  1:length(a);

% Loop through the vector
for na = aL

      % Get the elements from the current cell
      elementsFromCurrentCell = [a{na}];

      % Create index to all *other* cells, except for the current cell
      indexToOtherCells = setdiff(aL,na);

      % Concatenate all the elements from those other cells
      elementsFromAllOtherCells = [a{indexToOtherCells}];

      % Find the intersection between the current cell and all the other cells
      finalResult{na} = intersect(elementsFromCurrentCell,elementsFromAllOtherCells);

end

In order to get the "comparison" results, you just need to loop over each other cell in turn, rather than concatenating them all together the way I did to get the final result.

[Tha saliem]

Well Thank you so much for this detailed explanation. I have completely understood it. Thanks alot