MATLAB: Hourly average of multiple column data

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I have made a code to calculate hourly average of minute data. But it works only for single column. I have multiple column of concentration (BC) data. I want hourly average of multiple columns How can i get the desired answers. pls help.
    day1bc=BC(find((date==1)));
day1hour=hour(date==1);
maxday1=max(day1hour);
for i=1:maxday1
HI= find(day1hour==i);
  Bcv=day1bc(HI);
  mean_BC_hourly1(i,:)=mean(Bcv);
end
The input datas are:
day  hour   BC  BC;
1  1  10  20;
1  1  20  40;
1  2  30  60;
1  2  40  80;
1  3  50  100;
1  3  60  120;
1  3  70  140;
The answer expected:
BC   BC;
15  30;
35  70;
60  120;

Best Answer

Use accumarray for the hours, although you would have to loop over the days:
%      day hour BC  BC
Mtx = [ 1  1  10  20;
        1  1  20  40;
        1  2  30  60;
        1  2  40  80;
        1  3  50  100;
        1  3  60  120;
        1  3  70  140;];
% ‘for’     % LOOP OVER DAYS
    out(:,1) = accumarray(Mtx(:,2), Mtx(:,3), [], @mean);
    out(:,2) = accumarray(Mtx(:,2), Mtx(:,4), [], @mean);
% ‘end’     % LOOP OVER DAYS
In the loop over days, replace the ‘:’ in the ‘out’ array reference with the day number.
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