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Load time from netcdf file and retain the 'Hour' value

Asked by mashtine on 22 Jun 2015
Latest activity Commented on by suchitra rani on 24 Aug 2019
Hello,
I have a time variable (attached) that I created from using
netcdf_time = ncread('sample.netcdf','time');
When I use ncdisp on the netcdf file, time is described as the following:
time
Size: 102272x1
Dimensions: time
Datatype: int32
Attributes:
units = 'hours since 1900-01-01 00:00:0.0'
long_name = 'time'
calendar = 'gregorian'
My question is, what do I do with the netcdf_time variable to get the time into matlab datenum format while retaining the 'hour'. I have used this based on online phishing
time = double(netcdf_time/24 + datenum('1900-01-01 00:00:00'));
But, datestr(time(1:7,1),'dd-mm-yyyy HH:MM:SS') returns
01-01-1980 00:00:00
01-01-1980 00:00:00
01-01-1980 00:00:00
02-01-1980 00:00:00
02-01-1980 00:00:00
02-01-1980 00:00:00
02-01-1980 00:00:00
When it should return
01-01-1980 03:00:00
01-01-1980 06:00:00
01-01-1980 09:00:00
01-01-1980 12:00:00
01-01-1980 15:00:00
01-01-1980 18:00:00
01-01-1980 21:00:00
Any ideas?

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1 Answer

Answer by Ashish Uthama on 22 Jun 2015
 Accepted Answer

Instead of
time = double(netcdf_time/24 + datenum('1900-01-01 00:00:00'));
(netcdf/24 is still happening in int32, hence you are loosing precision)
Try
time = double(netcdf_time)/24 + datenum('1900-01-01 00:00:00');

  2 Comments

Worked! Thank you Ashish. Simple things fly straight over my head.

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