MATLAB: Unique rows of 2 cells with 2 columns each.

cellsmultiple columnsunique values

I have got 2 cells with 2 columns each:

IdxMembers(1636×2)

IdxMembers2(1630×2)

I am looking of the unique values of each cells in form of (nr. of unique values in first row x 2 columns)

I tried the following 2 codes:

unique(vertcat(IdxMembers,IdxMembers2),'rows')
and
unique(vertcat(IdxMembers,IdxMembers2))

I get the unique values in dim (nr. of unique values x 1 column). However, I would like get the output with the second column.

Do you have any suggestions?

Best Answer

I tried the following 2 codes: unique(vertcat(IdxMembers,IdxMembers2),'rows')... I get the unique values in dim (nr. of unique values x 1 column).

No, you really should have gotten 2 column output, as in the example below. Something about your situation must be different from what you are describing.

>> [IdxMembers,IdxMembers2] =deal( randi(3,4,2)  , randi(3,3,2))
IdxMembers =
     2     1
     2     2
     3     2
     3     2
IdxMembers2 =
     3     3
     3     2
     1     1
>> unique(vertcat(IdxMembers,IdxMembers2),'rows')
ans =
     1     1
     2     1
     2     2
     3     2
     3     3

Related Solutions

MATLAB: How to find unique values

The ‘Uvals’ array should have the information you want:

D = load('cat cat matlab2.mat');
a = D.a;
non_empty = cellfun(@(x)~isempty(x), a);
[r,c] = find(non_empty);
for k1 = 1:max(c)
    idx = r(c == k1);
    vals = a(idx,k1);
    Uvals{k1} = unique(vals);                   % Unique Values
end

MATLAB: How to find index of duplicate values in a matrix

Your example output (a 3x2 cell array) can only work if the numbers of repeat is the same for all repeated values. Otherwise you'll need a cell array of cell array. Furthermore, in general it's not a good idea to keep a [row, column] pair of indices, a linear index is more usually more useful.

Here is how I'd go about obtaining something similar to your desired output, that works regardless of the number of repeats:

A = [1 2 3 ; 4 2 3];
[uvalues, ~, uid] = unique(A(:));  
count = accumarray(uid, 1);   %easiest way to calculate the histogram of uvalues

linindices = accumarray(uid, (1:numel(A))', [], @(idx) {idx});  %split linear indices according to uid
valwhere = [num2cell(uvalues), linindices];  %concatenate
valwhere(count == 1, :) = []    %remove count of 1

The above gives you the list of linear indices. If you do really want the (row, column pairs):

A = [1 2 3 ; 4 2 3];
[uvalues, ~, uid] = unique(A(:));  
count = accumarray(uid, 1);   %easiest way to calculate the histogram of uvalues
[rows, cols] = ind2sub(size(A), (1:numel(A))');
rowcols = accumarray(uid, (1:numel(A))', [], @(idx) {num2cell([rows(idx), cols(idx)], 2)'});
valwhere = [num2cell(uvalues), rowcols];
valwhere(count == 1, :) = []

Best Answer

Related Solutions

MATLAB: How to find unique values

MATLAB: How to find index of duplicate values in a matrix

Related Question