Re: time conversion

Prior to using cd_calendar you should use a print

     print(time)
     date = ut_calendar(time,0)

It is possible that time does not contain some valis values

On 07/15/2011 10:33 AM, shinn wong wrote:
> Dear Dennis,
> Thank you for your help. I am using version 5.5.1. But when I used date
> = ut_calendar(time,0), missing value was returned. The dataset is too
> large to be sent. I would be much appreciated for any help and suggestion.
> Shinn
>
> 2011/7/11 Dennis Shea <shea@ucar.edu <mailto:shea@ucar.edu>>
>
> I don't use Matlab but maybe ...
>
> time = (/730848.5, 730848.9/)
> time@units = "days since Jan-1-0000 00:00:00"
>
> date = cd_calendar(time,0) ; year,month,day,hour,minute,sec
> print(date)
>
> Due to the way 'cd_calendar' defines the initial day, you may
> need to subtract 1 day
>
> So ...
>
> time = (/730848.5, 730848.9/) - 1 ; ?? adjust for different start day
> date = cd_calendar(time,0)
> print(date)
>
> =====
> The inverse is true also
>
> t = cd_inv_calendar(2001,5,19,0,0,__0,units,0) - 1 ; Matlab datenum
> print(t)
> ========
> cd_calendar is in v6.0.0
>
> if you have an older version of NCL use
>
> date = ut_calendar(time,0)
>
> BUT in ut_calendar year 0 is treated like year 1 ...
> so test to get the correct day
>
> # Year 0 is not treated as year 1, like it is with the ut_calendar
> and ut_inv_calendar functions.
>
> =======
>
>
> http://www.ncl.ucar.edu/__Document/Functions/Built-in/__cd_calendar.shtml
> <http://www.ncl.ucar.edu/Document/Functions/Built-in/cd_calendar.shtml>
>
> http://www.ncl.ucar.edu/__Document/Functions/Built-in/__cd_inv_calendar.shtml
> <http://www.ncl.ucar.edu/Document/Functions/Built-in/cd_inv_calendar.shtml>
>
> Good luck
>
>
> On 7/10/11 9:55 PM, shinn wong wrote:
>
> Dear all,
> I've got a netcdf file with time in the MATLAB datenum format (eg.
> 730848.5, 730848.9, etc). How can I convert it into a
> UT-referenced date
> using ncl? Thanks in advance for any help and suggestions.
> Regards,
> Shinn
>
>

-- 
======================================================
Dennis J. Shea                  tel: 303-497-1361    |
P.O. Box 3000                   fax: 303-497-1333    |
Climate Analysis Section                             |
Climate & Global Dynamics Div.                       |
National Center for Atmospheric Research             |
Boulder, CO  80307                                   |
USA                        email: shea 'at' ucar.edu |
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