How to extract some rows from a matrix and put them in another matrix?

I have a matrix

Q=[ 1 2 3 4; 4 3 2 1; 6 7 8 9]; N=[1 2 3 4; 6 7 8 9];

is there a function which output: Q=[4 3 2 1]; ? I mean a general function

I tried to delete all the rows which are in N from Q:

for j=1:size(N,1)
Q(all(Q==repmat(N(j,1:end) ,size(Q,1),1),2),:)=[];
end
Q;

Is there a one-line function? does this code I wrote is correct for any arbitrary N and Q?

Answer 1

[Stephen23]

>> idx = ismember(Q,N,'rows');
>> Q(idx,:) = []
Q =
   4   3   2   1

Answer 2

[JESUS DAVID ARIZA ROYETH]

setdiff(Q,N,'rows')