MATLAB: Collating rows based on constraints

Question

Hi

I have the following scenario, consider the matrix a a =

     1     2    10
     1     2    20
     2     1    11
     2     2    10
     2     1     1

I want to merge rows for the matrix a based on the first two columns where the first two columns have same values. My resultant should look like

res =

     1     2    30
     2     1    12
     2     2    10

How to do so with minimal or no loops.

Thanks

Answer 1

a=[ 1     2    10
    1     2    20
    2     1    11
    2     2    10
    2     1     1]
[ii,jj,kk]=unique(a(:,1:2),'rows','stable')
out=[ii accumarray(kk,a(:,3))]