How to find same elements in a cell array?

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Hello all,
I have the following question:
I need to find the same elements and how many times they are repeated in a cell array. The elements are vectors of integers (e.g, [1,3,4,5]). Then, I'd like to find the repeated sequences and the count of their repetitions.
For example, suppose that the cell array (C) is composed as follows:
[1,2,4,5] [1,4,2,5] [1,2,4,5] [4,1,5,2] [1,2,4,5] [1,4,2,5]
Is there any smart solution to get the sequences [1,2,4,5] and [1,4,2,5], and their repetitions (3 and 2, respectively)?
Thanks in advance,
Ale
  2 Comments
Azzi Abdelmalek
Azzi Abdelmalek on 14 Jul 2015
You mean [1,2,4,5] and [1,4,2,5], and their repetitions (3 and 2, respectively)

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Accepted Answer

Azzi Abdelmalek
Azzi Abdelmalek on 14 Jul 2015
Edited: Azzi Abdelmalek on 14 Jul 2015
a={[1,2,4,5] [1,4,2,5] [1,2,4,5] [4,1,5,2] [1,2,4,5] [1,4,2,5]}
b=cell2mat(a')
[ii,jj,kk]=unique(b,'rows')
out=[ii accumarray(kk,1)]
The last column of out is the frequency
  1 Comment
Alessandro Cristini
Alessandro Cristini on 14 Jul 2015
Edited: Alessandro Cristini on 14 Jul 2015
Thanks a lot! It is just what I wanted to do!!
But, in the case of one (or more) element is empty or doesn't agree with the size of the other one, this method doesn't work..
For example, suppose that the cell array "a" is composed as follows:
a={[1 2][1,2,4,5] [1,4,2,5] [1,2,4,5] [4,1,5,2] [1,2,4,5] [1,4,2,5][ ]}
In this case, how can I solve the above problem?
Thanks.

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More Answers (1)

Andrei Bobrov
Andrei Bobrov on 14 Jul 2015
Edited: Andrei Bobrov on 14 Jul 2015
a = {[1,2,4,5] [1,4,2,5] [1,2,4,5] [4,1,5,2,1] [1,2,4,5] [1,4, 2,5]};
a = a(:);
[a1,b,c] = unique(cellfun(@char,a,'un',0));
lo = histc(c,1:max(c));
loo = lo(:) > 1;
out = [a(b(loo)), num2cell(lo(loo))];
  1 Comment
Alessandro Cristini
Alessandro Cristini on 14 Jul 2015
Edited: Alessandro Cristini on 14 Jul 2015
I hadn't read this answer that solve my second question. Thanks for the help!

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