setdiff - returns components of a vector which do not belong to another one
setdiff(a,b) returns a sorted vector which retains the a entries which are not in b
[v,ka]=setdiff(a,b) returns a sorted vector which retains the a entries which are not in b and the location of these entries in a.
a = [223;111;2;4;2;2]; b = [2;3;21;223;123;22]; setdiff(a,b) [v,k]=setdiff(string(a),string(b))