MATLAB: How to get the length of the intersection of each row of a matrix with another vector

findintersectlengthmatrixvector

This is my scenario:
C = combnk(1:5, 3)
C =
   1   2   3
   1   2   4
   1   2   5
   1   3   4
   1   3   5
   1   4   5
   2   3   4
   2   3   5
   2   4   5
   3   4   5
And:
V =
   2   3
I need a new matrix with each row having the length of the intersection of each row of C with vector V, like this:
R =
    2
    1
    1
    1
    1
    0
    2
    2
    1
    1
Ideally I would like a new matrix that is a filtered C in which the resulting intersection length passes a given condition.
Sorry if this is pretty basic stuff, I don't seem to find the way to do it. Thanks!

Best Answer

Method one: ismember:
>> sum(ismember(C,V),2)
ans =
   2
   1
   1
   1
   1
   0
   2
   2
   1
   1
Method two: reshape and ==:
>> sum(sum(C==reshape(V,1,1,[]),3),2)
ans =
   2
   1
   1
   1
   1
   0
   2
   2
   1
   1
Method three: histc:
>> sum(histc(C,V,2),2)
ans =
   2
   1
   1
   1
   1
   0
   2
   2
   1
   1
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