MATLAB: How can do intersection and union of two vectors

matrixmatrix manipulation

Hello everyone, I have two vector A and B :
A=[256 1 6 8 4 5 78 25];
B=[85 22 1 25 2 589 6 3];
I want to have other vector result that consist of the union or the intersection of the elements in A and B like this:
 result_union=[256,85,1,22,6,8,25,4,2,5,589,78,25,3];
 result_intersect=[1,6,25];
Please, help me how can can I do it?

Best Answer

Intersection: simply use intersect with the stable option:
>> A = [256,1,6,8,4,5,78,25];
>> B = [85,22,1,25,2,589,6,3];
>> intersect(A,B,'stable')
ans =
     1     6    25
Union: to keep the order of the two vectors (like they were zipped or interleaved together), then you could concatenate the vectors and then use unique like this:
>> unique(reshape([A;B],1,[]),'stable')
ans =
   256    85     1    22     6     8    25     4     2     5   589    78     3
If the vectors have different lengths then you could use this FEX submission to zip them together (instead of the concatenation and rehsape in my example):
http://www.mathworks.com/matlabcentral/fileexchange/16919-interleave
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