MATLAB: I have 6 numbers with repetation : 1,2,2,3,3,4. I want all possible combinations using any 4 of the numbers. How will I get that

all possible combinations with repetationscombinationcombinations if there are one or more repeatitng elementspermutation

Generally I use 'nchoosek' function if there is no repetation. Example: A=1:6; combinations=nchoosek(A,4); combinations

Best Answer

You can still use nchoosek. Just use it to create indices into the vector rather than the vector itself:
v = [1,2,2,3,3,4];
Idx = nchoosek(1:size(v,2),4);
Out = v(Idx)
Out =
     1     2     2     3
     1     2     2     3
     1     2     2     4
     1     2     3     3
     1     2     3     4
     1     2     3     4
     1     2     3     3
     1     2     3     4
     1     2     3     4
     1     3     3     4
     2     2     3     3
     2     2     3     4
     2     2     3     4
     2     3     3     4
     2     3     3     4
Note the difference between ‘Idx’ and ‘’Out.
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