How to eliminate the elements in an array from another array?

Hi I have two arrays:

 a=[ 1 2 3 5 6 7 8 9 100];

 b=[1 2 3];

I want to eliminate the elements in b from a and gives me:

 c=[5 6 7 8 9 100]

How am I going to do this? Thanks in advance.

Answer 1

[Guillaume]

Assuming there's no repeating elements in a:

c = setdiff(a, b); %will also remove duplicates in a

If you have repeating elements and want to keep the duplicates:

c = a(~ismember(a, b));

[JC]

I don't think the second one could keep repeating elements...

Answer 2

[Zoltán Csáti]

Simply,

   c = a;
   c(b) = [];

[Guillaume]

No! That is completely wrong and only works because elements [1 2 3] also happen to be at index [1 2 3] in a. Try it with b = [100]