MATLAB-细胞阵列最重复的元素

Question

I have a cell array containing 5 1x2 arrays. Is there any way to find the most repeated element? I think I cannot use the "mode" function. I looked it up on the internet and could not find a solution about the problem. Everybody keeps talking about cells array with strings.

The cell array I'm using is like this: {[1 2], [2 5], [3 4], [1 2], [0 4]}

I would like MATLAB to find [1 2] as the most repeated element.

Thank you in advance.

Answer 1

For uniformly structured cell array (2 elements per cell) case

%// Convert the uniformly structured data to a 2D numeric array
Anum = vertcat(A{:})

%// ID unique rows and ID all rows based on those 
[~,unqID,ID ] = unique(Anum,'rows')

%// Use 'mode' on ID  and then index into unqID to get the index of 
%// the most frequently occurring cell and finally index into the 
%// input cell array with that index to get the desired output
out = A{unqID(mode(ID))}

Thus, for the given input data -

A = {[1 2], [2 5], [3 4], [1 2], [0 4]}

You would have -

out =
     1     2

---

More generic case with cells of row vectors

If you are dealing with a cell array that has arbitrary sized row vectors in each cell, you can use this technique -

%// Get all elements of A
A_ele = [A{:}]

%// Get lengths of each cell
lens = cellfun('length',A)

%// Setup a 2D numeric array corresponding to the input cell array
A_num = zeros(max(lens),numel(lens))+max(A_ele)+1
A_num(bsxfun(@ge,lens,[1:max(lens)]')) = A_ele  %//'

%// ID each row, find the mode with those & finally have the desired output
[unqrows,unqID,ID ] = unique(A_num.','rows')  %//'
out = A{unqID(mode(ID))}

Thus, if you have input as -

A = {[1 2], [2 5], [3 4], [1 2], [0 4], [1 2 1],[9],[7 2 6 3]}

The output would still be -

out =
     1     2

Answer 2

This works for a general cell array A :

A = {[4 2] [2 5] [4 2] [1 2 1] [9] [7 2 6 3] [1 2 1] [1 2 1] [7 9]}; %// example data
[ii, jj] = ndgrid(1:numel(A)); %// ii, jj describe all pairs of elements from A 
comp = cellfun(@isequal, A(ii), A(jj)); %// test each pair for equality
[~, ind] = max(sum(comp,1)); %// get index of (first) most repeated element
result = A{ii(ind)}; %// index into A to get result