[ncl-talk] Calendar attribute for time_to_newtime !!! Developer Attention !!!

[Alan Brammer]

What version of ncl are you using? I just tested a similar few lines of
code in 6.1.1 and 6.2.0 and they both copied the calendar attribute as
expected. Also have you tried cd_convert() seems to do the same thing?

However in these tests and looking around I have a strong suspicion there
is a significant bug in this function.  In that the code copies the
calendar attribute but does not actually make use of it and thus returns
the wrong answer disguised as the correct one.


Attached is my edited code.  load this below a load "....contibuted.ncl"
line if you have one and this version of the code will replace the stock
version.  A developer will hopefully weigh in with more insight in this.


Good luck,

Alan





On Fri, Oct 3, 2014 at 10:08 PM, Lam Hoang <lamhpvn at gmail.com> wrote:

> Dear NCL supporting team,
> I want to convert the time units from a CMIP5 model to make them unique.
> I try to use time_to_newtime function but unfortunately after convert the
> time units, the calendar attribute changes to "gregorian" as well.
> What should I do if I want to keep the calendar attribute as the original
> time variable?
>
> Regards,
> Lam
>
>
> f =
> addfile("./oldtime_psl_day_NorESM1-M_historicalExt_r3i1p1_20060101-20121231.nc","r")
> temp = f->psl
> t = f->time
>
> printVarSummary(t)
>
> *** Variable: t
>
> *** Type: double
>
> *** Total Size: 20440 bytes
>
> ***             2555 values
>
> *** Number of Dimensions: 1
>
> *** Dimensions and sizes: [time | 2555]
>
> *** Coordinates:
>
> ***             time: [ 0.5..2554.5]
>
> *** Number Of Attributes: 6
>
> ***   bounds : time_bnds
>
> ***   units : days since 2006-01-01 00:00:00
>
> ***   calendar : noleap
>
> ***   axis : T
>
> ***   long_name : time
>
> ***   standard_name : time
>
> t = time_to_newtime(t, "days since 1850-01-01 00:00:00")
>
> printVarSummary(t)
>
> *** Variable: t
>
> *** Type: double
>
> *** Total Size: 20440 bytes
>
> ***             2555 values
>
> *** Number of Dimensions: 1
>
> *** Dimensions and sizes: [time | 2555]
>
> *** Coordinates:
>
> ***             time: [56978.5..59534.5]
>
> *** Number Of Attributes: 6
>
> ***   calendar : gregorian
>
> ***   units : days since 1850-01-01 00:00:00
>
> ***   bounds : time_bnds
>
> ***   axis : T
>
> ***   long_name : time
>
> ***   standard_name : time
>
>
> --
> Hoang Phuc Lam
> Viet Nam National Center of Hydro-Meteorology Forecasting
> National Hydro-Meteorological Services of Vietnam
> Mob: +84 12 1616 5258
> Tel:   +844 38247002
> Fax:  +844 38254278
>
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>
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