"setdiff" comand usage ?

when i run this code:

    a=[1 1 2];
    b=[1];
    setdiff(a,b)

i get this:

>> c

ans =

       2

but I want this:

    >> c 

    ans = 

         1  2

What should I do to fix this ?

Answer 1

[Torsten]

https://de.mathworks.com/matlabcentral/answers/406227-excluding-one-vector-from-another-vector-with-repetition

Answer 2

[KSSV]

B2 = union(a,b)

[IBM watson]

Yes but algorithm should be able do this in a loop. I cant check it every time. Because if b was b=[2] then i get wrong results.