Clustering data from index

Good morning, I have a matrix like this

ID =

         10032       10033
         10140       10141
         10604       10607
         10610       10611
         10615       10626
         11199       11201
         11200       11203
         11279       11365
         11283       11380
         11605       11606
         11635       11972
          1168        1169
            11         382
            11         505
            11         617
            11         761
            11         975
            975        1320
            3000       617

And I want to get all the families for which a same shared number is available for example a family will contain all these couples:

family = [11         382;
          11         505;
          11         617;
          11         761;
          11         975;
          975        1320;
          3000       617]

Do you have any idea about how to cluster this data?

Thanks in advance!

Answer 1

[KSSV]

k = mode(ID(:,1)); % Gets most frequent number 
idx = find(ID(:,1)==k) ;   % get the indices where k=11 is 
iwant = ID(idx,:)

[Piero Poli]

Thanks, however I would like to iterate this process to get all possible families. For examples some families will have just a couple of index (e.g. one line of ID). Any suggestions?

Also, you code is not finding the last two couples of the family one:

 975        1320
3000       617

Thank you

Answer 2

[Andrei Bobrov]

[a,~,c] = unique(ID);
out = ID(any(ismember(ID,a(accumarray(c,1) > 1)),2),:);

[Piero Poli]

Thank you Andrei, unfortunately this lines are not providing the output. I was looking for a way to come out with group of families all sharing at the same index, just as show in the family matrix in my question. At the end I would like to have N families.

Thank you

[Andrei Bobrov]

function cl = fun_for_piero(ID)

[a,~,c] = unique(ID);
ii = reshape(c,size(ID));
k = 1;
i1 = 1;
cl{k} = [];
c = 1:numel(a);
while ~isempty(ii)
    t = any(ismember(ii,i1),2);
    if ~any(t)
        k = k + 1;
        cl{k} = [];
        i1 = c(1);
    else
        p = unique(ii(t,:));
        cl{k} = [cl{k};sort(a(p(:)))];
        ii = ii(~t,:);
        c = setdiff(c,p);
        i1 = p(:);
    end
end