how to take mean of variables from 00 and 12 GMT observations?

% Load the grouping data

lat = ncread(ncfile,'latitude');
lon = ncread(ncfile,'longitude');
expver = ncread(ncfile,'expver');
time = ncread(ncfile,'time');
time = datetime(double(time)*60*60,'ConvertFrom','epochtime','Epoch','1901-01-01');
% convert grouping data to 4x4x2x6961 arrays
[Lon,Lat,Expver,Time] = ndgrid(lon,lat,expver,time);
dataTbl = timetable(Time,Lon,Lat,Expver,d2m,t2m,e,pev,ssr,ssrd,tp,vpd,rh)
% Calculate the mean over latitude x longitude x time
data = groupsummary(dataTbl,["Time","Time"],["hourofday","day"],"mean",4:12)

The above code computes daily average for each day over Lat X Lon and writes

the data of number of rows 3482 for 00 GMT and 3481 for 12 GMT out of total number of observations as 6963. I wish to

calculate the daily average for each day from 00 and 12 GMT also. Therefore,

the dimension of output file becomes (3481,9).

I request you all to please suggest me how to do it in above mentioned code.

Sanchit

[Cris LaPierre]

EDIT: OP deleted their posts.

how to take mean of variables from 00 and 12 GMT observations?

% Load the grouping data
lat = ncread(ncfile,'latitude');
lon = ncread(ncfile,'longitude');
expver = ncread(ncfile,'expver');
time = ncread(ncfile,'time');
time = datetime(double(time)*60*60,'ConvertFrom','epochtime','Epoch','1901-01-01');
% convert grouping data to 4x4x2x6961 arrays
[Lon,Lat,Expver,Time] = ndgrid(lon,lat,expver,time);
dataTbl = timetable(Time,Lon,Lat,Expver,d2m,t2m,e,pev,ssr,ssrd,tp,vpd,rh)
% Calculate the mean over latitude x longitude x time
data = groupsummary(dataTbl,["Time","Time"],["hourofday","day"],"mean",4:12)

The above code computes daily average for each day over Lat X Lon and writes

the data of number of rows 3482 for 00 GMT and 3481 for 12 GMT out of total number of observations as 6963. I wish to

calculate the daily average for each day from 00 and 12 GMT also. Therefore,

the dimension of output file becomes (3481,9).

I request you all to please suggest me how to do it in above mentioned code.

Sanchit

_______________________________________________________________________________

Response

Why start a duplicate question, especially since the code you are posting here is from my answer there?

Original question can be found here: https://www.mathworks.com/matlabcentral/answers/1997658-how-do-i-compute-mean-values-of-nine-variables-over-lat-x-lon-x-time

________________________________________________________________________________

OP

Dear Cris LaPierre,

This is not a duplicate question but it is partly unanswered question. I requested in my first post to get daily mean of all the variables each day for 00 and 12 GMT observations also. But this code does not do that. That is why I have again posted this code to get my answer. I request you to please suggest me how to get daily mean of nine variables each day from 00 and 12 GMT also using this code. I would be grateful to you for your kind help.

Sanchit

[Cris LaPierre]

It does do that. I've commented as much in the original question.

______________________________________________________________________________

OP

But I am getting the 00 and 12 GMT data seperately written in my output file. The dimension of output file should be (3481,11) not (6963,11). Please I request you to get the mean of 00 and 12 GMT data also.

Sanchit

[Devendra]

Hi Cris, Is it possible to get the mean of 00 and 12GMT observations also for nine variables in addition to mean over Lat x Lon boxes using the above code?

I am curious to know. Would greatly appreciate your reply. Devendra Chahar

[Cris LaPierre]

Yes. See the explanation here.

[Rena Berman]

(Answers Dev) Restored edit

Answer 1

[Walter Roberson]

Now that you have a timetable, you can retime asking for 'hourly'

[Sanchit]

Thank you very much for your kind suggestion. May I request you to please suggest me how to do it in above mentioned code. I would be grateful to you for your kind help.

Sanchit

[Walter Roberson]

retime(dataTabl(:,4:12), 'hourly', 'mean')