Question 1: yes, please look at the "Date" functions at:
http://www.ncl.ucar.edu/Document/Functions/
Specifically, 'isleapyear'
-- Question 2: This is fundamental to NCL. The @ means an atrtribute of a variable It means that it will be written to a netCDF file. time_at_units is a variable. === Please read the documentation at http://www.ncl.ucar.edu/Document/Manuals/ As a start ... the Mini-Langiage Manual On 4/5/12 1:43 AM, Mark Chan wrote: > Dear Dennis, > > It works, thanks very much! > The data file is too large to send by email. Besides, this question has > nothing to do with CDO, which I just use here to show data info. > > In addition, I have another two questions as: > > Question-1:If I know a specific year, e.g. 2009, is there any NCL > function to judge whether it is a leap year? > > Question-2: > What is the difference about > time_at_units = "yyyymmdd" > and > time@units = "yyyymmdd" > > Thanks very much again! > Mark > > ------------------------------------------------------------------------ > *From:* Dennis Shea <shea@ucar.edu> > *To:* Mark Chan <cym263@yahoo.com> > *Cc:* "ncl-talk@ucar.edu" <ncl-talk@ucar.edu> > *Sent:* Thursday, April 5, 2012 1:13 AM > *Subject:* Re: [ncl-talk] warning:FileVarAttDef: Variable (time) has no > attributes to assign > > You should send this to the CDO mailing list. > > The original ASCII file 'ecmwf_temp_2009_monthly_mean.dat' > is not available nor is the netCDF file the script created. > > *speculation* > > To be CF compliant, I believe the 'time' variable must have > units of the form > > "hours since ..." or "seconds since ..." or ""days since" > > You can specify an arbitrary start date in the units. > > See: > > http://www.ncl.ucar.edu/Document/Functions/Built-in/cd_inv_calendar.shtml > > You could have an 'auxiliary time variable, eg > > date = ... > date!0 = "time" > date@units = "yyyymmdd" > > > On 4/4/12 8:09 AM, Mark Chan wrote: > > Dear NCL users, > > > > The attached file is my NCL script, that is used for writing netCDF > > file. It works but always show a warning message as: > > warning:FileVarAttDef: Variable (time) has no attributes to assign > > > > Can someone help to get rid of this warning message? I wish you could > > give more suggestion to make it better, and moreover, give an advice for > > writting "hourly" data. > > > > Thank you very much! > > Mark > > > > --------------created data info----------------------------- > > >$ cdo info my_simple.nc <http://my_simple.nc> > > -1 : Date Time Param Level Size Miss : Minimum Mean Maximum > > 1 : 2009-01-01 00:00:00 -1 0 1036800 0 : -49.800 4.2846 35.400 > > 2 : 2009-02-01 00:00:00 -1 0 1036800 0 : -48.600 3.3501 34.400 > > 3 : 2009-03-01 00:00:00 -1 0 1036800 0 : -56.900 3.1774 33.800 > > 4 : 2009-04-01 00:00:00 -1 0 1036800 0 : -69.000 4.2939 35.500 > > 5 : 2009-05-01 00:00:00 -1 0 1036800 0 : -63.600 6.5704 38.300 > > 6 : 2009-06-01 00:00:00 -1 0 1036800 0 : -61.200 7.7993 38.600 > > 7 : 2009-07-01 00:00:00 -1 0 1036800 0 : -58.700 8.4162 40.000 > > 8 : 2009-08-01 00:00:00 -1 0 1036800 0 : -67.200 7.7216 40.300 > > 9 : 2009-09-01 00:00:00 -1 0 1036800 0 : -65.100 6.8033 36.400 > > 10 : 2009-10-01 00:00:00 -1 0 1036800 0 : -54.400 5.8541 34.200 > > 11 : 2009-11-01 00:00:00 -1 0 1036800 0 : -39.500 5.1426 33.600 > > 12 : 2009-12-01 00:00:00 -1 0 1036800 0 : -51.600 4.5734 34.000 > > cdo info: Processed 12441600 values from 1 variable over 12 timesteps. ( > > 0.47s ) > > > > > > > > _______________________________________________ > > ncl-talk mailing list > > List instructions, subscriber options, unsubscribe: > > http://mailman.ucar.edu/mailman/listinfo/ncl-talk > > _______________________________________________ ncl-talk mailing list List instructions, subscriber options, unsubscribe: http://mailman.ucar.edu/mailman/listinfo/ncl-talkReceived on Thu Apr 5 08:54:43 2012
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