Finding 8 day averages for timeseries data

I have two data types; daily runoff and 8-day chlorophyll.

I've created loops to generate monthly and yearly averages for the chlorophyll and runoff, but am not sure how to make 8-day averages for the runoff.

Here is one of my yearly loops

year_counter = 1;
y2 = runoff_loop_dates(:,1);
yearUN = unique(y2);
for ii = 1:length(yearUN)
        idx = find(y2==yearUN(ii));
        runoff_year(ii) = nanmean(runoff(idx));
        year_counter = year_counter + 1;
end

How can I change this to find 8-day averages? Thank you.

Answer 1

[Adam Danz]

Convert your data to a timetable and use retime to compute monthly/yearly/8-day averages (also see array2timetable).

If you have any trouble, share your updated code in a comment and I'd be happy to help straighten things out.

[Amy07]

Thank you so much for taking the time to reply - my code is working now. (retime is a much easier method than the one I was using!)