將2分鐘的數據轉換爲15分鐘的平均值

Question

假設我每隔2分鐘收集一次數據並計算15分鐘的平均值，那麼考慮到2不會進入15，我該怎麼做呢？

說，如果我有一個數據集，像這樣

time = {'2009-01-15 00:02';'2009-01-15 00:04';... 
    '2009-01-15 00:06';'2009-01-15 00:08';'2009-01-15 00:12';... 
    '2009-01-15 00:14';'2009-01-15 00:16';... 
    '2009-01-15 00:18';'2009-01-15 00:20';... 
    '2009-01-15 00:22';'2009-01-15 00:24';'2009-01-15 00:26';... 
    '2009-01-15 00:28';'2009-01-15 00:30'}; 
dat = [1,3,1,4,2,5,6,1,3,1,4,2,5,6]; 

我怎麼會計算15分鐘，平均？

Answer 1

代碼 -

% Edit this based on your choice of starting from 00:00 or from the first entry 
start_from_0000 = false; 

% Performing Code 
datenum_mins = datenum(time)*24*60; 
if start_from_0000 
    start1 = floor(datenum(time(1)))*24*60; 
    ind_15min_periods = floor((datenum_mins - start1)./15)+1; 
else 
    ind_15min_periods = floor((datenum_mins - datenum_mins(1))./15)+1; 
end 

mean_dat = zeros(max(ind_15min_periods),1); 
for c1 = 1:max(ind_15min_periods) 
    mean_dat(c1) = mean(dat(ind_15min_periods==c1)); 
end