loop for exctracting daily data for january, february, december,

I have 3 dimensional data (10x10x25933), it is hourly data from 1950-1-1 to 2020-12-31. how to make a loop to extract daily data for January, February, and december.

Here is my code for 1 grid point;

t1=(datetime(1950,1,1):hours(24):datetime(2020,12,31))';

t1.Format = 'yyyy-MM-dd hh:mm:ss';

TT=timetable(t1,T);

RT = ismember(month(TT.t1),[1,2,12]);

TTT = TT(RT,:);

Tdjf=TTT.T(TTT.t1);

File link

https://drive.google.com/file/d/1YrF2aKAxp7mym5fXJyctQW44058pfBtE/view?usp=sharing

[Stephen23]

Your original approach was much better than using deprecated date functions. Do NOT use DATEVEC.

DT = datetime(1950,1,1):caldays(1):datetime(2020,12,31);
DT = DT(:)

DT = 25933×1 datetime array
   01-Jan-1950
   02-Jan-1950
   03-Jan-1950
   04-Jan-1950
   05-Jan-1950
   06-Jan-1950
   07-Jan-1950
   08-Jan-1950
   09-Jan-1950
   10-Jan-1950
   11-Jan-1950
   12-Jan-1950
   13-Jan-1950
   14-Jan-1950
   15-Jan-1950
   16-Jan-1950
   17-Jan-1950
   18-Jan-1950
   19-Jan-1950
   20-Jan-1950
   21-Jan-1950
   22-Jan-1950
   23-Jan-1950
   24-Jan-1950
   25-Jan-1950
   26-Jan-1950
   27-Jan-1950
   28-Jan-1950
   29-Jan-1950
   30-Jan-1950

DT.Month % easiest and most efficient

ans = 25933×1

1 1 1 1 1 1 1 1 1 1

for example:

idx = ismember(DT.Month,[1,2,12]);

It is not clear from your question if you expect to get three groups (one for each of the requested months), or one group containing all of the data for all of the requested months. Please clarify.

Answer 1

[KSSV]

t1=(datetime(1950,1,1):hours(24):datetime(2020,12,31))';
t1.Format = 'yyyy-MM-dd hh:mm:ss'; 
[y,m,d,H,M,S] = datevec(t1) ;   % this will give year, monthm day, hour, minute, second 
% extract january 
idx = m==1 ;  % Jan is month = 1 
iwant = data(:,:,idx) ;  % where data is your 10x10x25933 matrix 

[Muhammad Uswah Pawara]

Thank you so much

[Stephen23]

Do NOT use deprecated DATEVEC, DATENUM, or DATESTR!