Assuming original data is in matrix A:
indx=unique(A(:,1));
for ii=1:numel(indx)
  RowMean(ii,:)=mean(A(1,:)==indx(ii),:);
end
2
solved Calculate the mean of set of rows in a matrix [duplicate]
 
Assuming original data is in matrix A:
indx=unique(A(:,1));
for ii=1:numel(indx)
  RowMean(ii,:)=mean(A(1,:)==indx(ii),:);
end
2
solved Calculate the mean of set of rows in a matrix [duplicate]