| MATLAB Functions | Help Desk |
ismember
Detect members of a set
k = ismember(a,S) k = ismember(A,S,'rows')
k = ismember(a,S)
returns an vector the same length as a containing logical true (1) where the elements of a are in the set S, and logical false (0) elsewhere. In set theoretic terms, k is 1 where a 
S.
k = ismember(A,S,'rows')
when A and S are matrices with the same number of columns returns a vector containing 1 where the rows of A are also rows of S and 0 otherwise.
set = [0 2 4 6 8 10 12 14 16 18 20];
a = reshape(1:5,[5 1])
a =
1
2
3
4
5
ismember(a,set)
ans =
0
1
0
1
0
intersect Set intersection of two vectors
setdiff Return the set difference of two vectors
setxor Set exclusive-or of two vectors
union Set union of two vectors
unique Unique elements of a vector