MATLAB: How to calculating monthly average

average

hi all I just want to be sure about this small monthly averaging code
 I=1;
 for i=1: length(x)/30; 
    y(i)=mean(x(I:I+29));
    L(i)=min(x(I:I+29));
    U(i)=max(x(I:I+29));
    I=I+29;
 end
where x is data matrix (365 day)
thank you

Best Answer

Try this:
dailyValues = rand(1,365);  % Sample data
daysInMonths = [31,28,31,30,31,30,31,31,30,31,30,31]
monthEnds = [0, cumsum(daysInMonths)]
for m = 1 : length(monthEnds)-1
  firstDay = monthEnds(m)+1;
  lastDay = monthEnds(m+1);
  fprintf('For month #%d, the first day = %d and the last day = %d\n',...
    m, firstDay, lastDay);
  monthlyAverage(m) = mean(dailyValues(firstDay:lastDay));
end
% Echo to command window.
monthlyAverage
Of course you need to take leap years into account, which I didn't do.
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