MATLAB - 單元陣列的最重複元素

Question

我有一個單元陣列包含5個1x2陣列。有什麼方法可以找到最重複的元素嗎？我想我不能使用「模式」功能。我在網上查了一下，找不到解決問題的辦法。每個人都一直在討論帶有字符串的單元陣列。

我使用的單元陣列是這樣的： {[1 2]，[2 5]，[3 4]，[1 2]，[0 4]}

我想MATLAB找到[1 2]作爲最重複的元素。

預先感謝您。

Answer 1

對於統一的結構化單元陣列（每單元2個元件）的情況下

%// 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))} 

因此，對於給定輸入數據 -

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

你將不得不 -

out = 
    1  2 

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與行的細胞更通用的情況下，向量

如果正在處理與在每個單元具有任意大小的行向量的單元陣列，則可以使用這種技術 -

%// 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))} 

因此，如果你必須輸入作爲 -

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

輸出仍然是 -

out = 
    1  2 

Answer 2

這適用於一般單元陣列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