intersect:取交集，http://www.matkk.com/intersect.html

unique：取各自独立的部分，http://www.matkk.com/unique.html

union：取并集（当然，去了冗余），http://www.matkk.com/union.html

Matlab中集合的交运算函数intersect

intersect
Set intersection of two vectors

Syntax

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. A and B can be cell arrays of strings.

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

1     2     3     6
     1     2     3     4
     1     2     3     5

See Also

ismember, issorted, setdiff, setxor, union, unique