# How to calculate averaged values from 5-min interval values

15 views (last 30 days)
Daphne PARLIARI on 19 Sep 2019
Commented: Daphne PARLIARI on 31 Oct 2019
Hello guys.
I have the following question : I have observations for temperature in 5-minute interval, from 1/1/2015 to 31/1/2015 (8928 rows in total). From these data I must extract the hourly average value for temperature, which means that eventually I must have 24 hourly averaged values.
I would appreciate any ideas on the matter!
PS. I have attached the excel file I'm working on. Please note that the format of time appears diferently on Matlab.

David K. on 19 Sep 2019
Edited: David K. on 25 Sep 2019
Using for loops is a very straightforward way that this can be done:
size1 = length(x)/12;
size2 = 24;
sub1 = ones(size1,1); % intermediate matrix for averaging every hour
for n = 1:size1 % 8928/12 = 744
sub1(n) = mean(x(12*(n-1)+1 : (12*n))); % averages every 12 values to average every hour
end
hourlyVals = ones(size2 , 1); % 744/31 = 24
for n = 1:size2
hourlyVals(n) = mean(sub1(n:24:size1)); % calculate average of each hour across every day.
end
*edited to fix issue brought up in comments*
David K. on 1 Oct 2019
So I looked at the excel table itself to calculate the mean and it had the same flipped situation. Since it appears that if we only look at the first few days it is as expected then I think it is possible there is something wrong with the data. Your data stops at the 11th hour instead of the full 24 for the last day. perhaps at some point the data got off. I do not know how you would figure it out but I think that is up to you with your data.
To fix the RH I would do the same thing as last time where you just find the places it is missing and fix it manually.
Daphne PARLIARI on 2 Oct 2019
If I delete the last 12 values in order to have all the days with 24 hourly values, then the shape of the diurnal variation of T is correct but the values are too low.
If I add again the last 12 values, the curve loses its shape but the hourly values are correct. It seems that I can't have it both ways.

Andrei Bobrov on 1 Oct 2019
Edited: Andrei Bobrov on 1 Oct 2019
T = T(~isnan(T.minute),[1:5,7:8]);
T.YEAR = str2double(T.YEAR);
T{:,{'AIR_TEMP_DegC','RH'}} = str2double(T{:,6:7});
T = T(:,[1:5,8:9]);
T_hour = varfun(@(x)mean(x,'omitnan'),T,'InputVariables',{'AIR_TEMP_DegC','RH'},'GroupingVariables','HOUR');
Daphne PARLIARI on 2 Oct 2019
Your help was crucial! Thank you a million times!
Daphne PARLIARI on 31 Oct 2019
Dear Andrei, I would like to ask a further question on your code which has worked dreamily.
Is there a way to create an intermediate matrix (before extracting the 24 hourly values of T) which will contain one hourly value of temperature for every hour of each day? With this, I need to have a temperature at 00.00 on 1/1/2015, temperature at 01.00 on 1/1/2015 and so on until 23.00 on 31/5/2015.
Is this applicable?

### Categories

Find more on Time Series Objects in Help Center and File Exchange

R2016a

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!