Re: [thredds] NcML Aggregation Question - Not wanting time as strings

• To: Bob Simons <Bob.Simons@xxxxxxxx>
• Subject: Re: [thredds] NcML Aggregation Question - Not wanting time as strings
• From: Rich Signell <rsignell@xxxxxxxx>
• Date: Wed, 7 Sep 2011 12:36:05 -0400

This has been a long-standing request to the NetCDF-Java/TDS
development group.  I second the motion again for CF-compliant times
on aggregation type="joinNew"!

-Rich

On Wed, Sep 7, 2011 at 12:26 PM, Bob Simons <Bob.Simons@xxxxxxxx> wrote:
> I will add that:
> my reading of the CF standard is that coordinate (AKA axis, AKA dimension)
> variables must be numeric:
> http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.4/cf-conventions.html#terminology
> says
> "coordinate variable
> We use this term precisely as it is defined in section 2.3.1 of the NUG. It
> is a one-dimensional variable with the same name as its dimension [e.g.,
> time(time)], and it is defined as a numeric data type with values that are
> ordered monotonically. Missing values are not allowed in coordinate
> variables. "
>
> So, it would be great if THREDDS could extract the date coordinates from the
> file names and make a *numeric* time coordinate/axis/dimension variable.
>
> I know that choosing the units brings up other issues. Perhaps they could be
> specified by the THREDDS administrator, or perhaps THREDDS could just always
> use units="seconds since 1970-01-01".
>
>
> On 9/6/2011 3:37 PM, Roy Mendelssohn wrote:
>>
>> Hi All:
>>
>> The following has come up in a problem we are working on:
>>
>>> I'd like to aggregate files as in the example toward the bottom of:
>>>
>>> http://www.unidata.ucar.edu/software/netcdf/ncml/v2.2/Aggregation.html
>>>
>>> "Extracting date coordinates from the filename"
>>>
>>> The text in the tutorial states:
>>>
>>> 'The net effect is to add a coordinate variable, whose values are ISO
>>> 8601 formatted date/time Strings, with a _CoordinateAxisType of
>>> "Time" ..."
>>>
>>> Is there any for this variable to be a timestamp rather than date/time
>>> Strings?
>>
>> Listing the values is not that practical since there are over 3000 files
>> and the number will grow.  Thanks for any help.
>>
>> -Roy
>>
>> **********************
>> "The contents of this message do not reflect any position of the U.S.
>> Government or NOAA."
>> **********************
>> Roy Mendelssohn
>> Supervisory Operations Research Analyst
>> NOAA/NMFS
>> Environmental Research Division
>> Southwest Fisheries Science Center
>> 1352 Lighthouse Avenue
>> Pacific Grove, CA 93950-2097
>>
>> e-mail: Roy.Mendelssohn@xxxxxxxx (Note new e-mail address)
>> voice: (831)-648-9029
>> fax: (831)-648-8440
>> www: http://www.pfeg.noaa.gov/
>>
>> "Old age and treachery will overcome youth and skill."
>> "From those who have been given much, much will be expected"
>> "the arc of the moral universe is long, but it bends toward justice" -MLK
>> Jr.
>>
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>
> --
> Sincerely,
>
> Bob Simons
> IT Specialist
> Environmental Research Division
> NOAA Southwest Fisheries Science Center
> 1352 Lighthouse Ave
> Pacific Grove, CA 93950-2079
> Phone: (831)658-3205
> Fax:   (831)648-8440
> Email: bob.simons@xxxxxxxx
>
> The contents of this message are mine personally and
> do not necessarily reflect any position of the
> Government or the National Oceanic and Atmospheric
> Administration.
> <>< <>< <>< <>< <>< <>< <>< <>< <><
>
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-- 
Dr. Richard P. Signell   (508) 457-2229
USGS, 384 Woods Hole Rd.
Woods Hole, MA 02543-1598

• References:
  • [thredds] NcML Aggregation Question - Not wanting time as strings
    • From: Roy Mendelssohn
  • Re: [thredds] NcML Aggregation Question - Not wanting time as strings
    • From: Bob Simons