find the same values and average it out

I have the following matrix A:

A =
  66  2
  66  3
  66  4
  67  6
  67  3
  68  5
  69  6
  69  3

what I would like to do is find the values that are the same in the first column and average the values in the second column and put it into a new matrix (B).

for example: I look for "66" and average the corresponding values in the second columns (i.e. 2,3,4) and the the mean is 3. So the first entry in matrix B will be:

B = 
66  3

Answer 1

[Azzi Abdelmalek]

A =[  66  2
  66  3
  66  4
  67  6
  67  3
  68  5
  69  6
  69  3]
[ii,jj,kk]=unique(A(:,1))
out=[ii accumarray(kk,A(:,2),[],@mean)]