MATLAB Functions

Set intersection of two vectors

c = intersect(a,b)
c = intersect(a,b,'rows')
[c,ia,ib] = intersect(...)

Description

c = intersect(a,b)

returns the values common to both A and B. The resulting vector is sorted in ascending order. In set theoretic terms, this is
a

b. Non-vector input arrays are regarded as column vectors a = A(:) or
b = B(:).

c = intersect(a,b,'rows')

when a and b are matrices with the same number of columns returns the rows common to both a and b.

[c,ia,ib] = intersect(a,b)

also returns column index vectors ia and ib such that c = a(ia) and c = b(ib) (or c = a(ia,:) and c = b(ib,:)).

Examples

A = [1 2 3 6]; B = [1 2 3 4 6 10 20];    
[c,ia,ib] = intersect(A,B);
disp([c;ia;ib]) 
     1     2     3     6
     1     2     3     4
     1     2     3     5