MATLAB: How to average rows which contain the same first to elements

equalmatrixmeanrows

I'm stuck on this problem for a while. I want to obtain a matrix which is averaged for the rows which contain the same first two elements. I don't want to clear the rows which are not equal for the first two elements. When I have a matrix A:
A=[1     1     1     1     1
   1     2     3     4     5
   1     2     4     4     4
   1     2     3     3     3
   2     2     2     2     2
   2     2     3     3     3]
I want the outcome to be:
 A=[1    1    1     1     1
    1    2   3.33  3.67   4
    2    2   2.5   2.5   2.5]
I hope someone could help me on this.

Best Answer

This solution is not very elegant, but should work. There is room for improvement, though.
    uA = unique(A(:,1:2),'rows');
    A = [uA cell2mat(cellfun(@(x)...
         mean(A(all(bsxfun(@eq,A(:,1:2),x),2),3:end),1), ...
         num2cell(uA,2),...
         'UniformOutput',false)) ]
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