Re: [netcdf-java] problem with aggregation of files with relative time axis

You're welcome.  I just looked at how we did it in the IDV. ;-)

Glad it's working for you.

Don

On 1/8/18 11:17 AM, Etienne Tourigny wrote:
On 01/08/2018 06:56 PM, Don Murray (NOAA Affiliate) wrote:
Hi Etienne-

Add the timeUnitsChange attribute to the aggregation element:


<netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
   <aggregation dimName="time" type="joinExisting" timeUnitsChange="true">
     <scan location="/esarchive/scratch/etourign/work/loader/tmp/"
suffix=".nc" />
   </aggregation>
</netcdf>

and you will get the right dates.

Brillant! thank you so much, I was sure there was a way to fix this easily.

Somehow I overlooked this piece of information which is clearly
documented in the NcML Aggregation docs.

If you do not specify a coordinate variable, one must exist in each of
the nested datasets, and the coordinate values will be read from it,
just like any other aggregation variable. In this case, when the units
of the aggregation coordinate change on the existing coordinate
variables, you must add timeUnitsChange="true" on the aggregation element:

many thanks,
Etienne

Don Murray



On 1/8/18 10:38 AM, Etienne Tourigny wrote:
Hi all,

I have problems reading a collection of netcdf files which use a
relative time axis, and each file has a time axis relative to a
different date.

When reading the aggregated files using a ncml file, the computed dates
are random and most of the time wrong.

For example, if I have 3 files with a time axis relative to the 1st of
January, February and March, sometimes netcdf-java decides that the
collection starts on March 1st, and sometimes on January 1st.

If I modify the files to all have a time axis relative to the same date
(e.g. January 1st) then things are fine.

Any hints?

Attaching the netcdf files (a spatial subset of the actual files) and
the ncml file, hope they go through.

Many thanks,

Etienne



http://bsc.es/disclaimer



_______________________________________________
NOTE: All exchanges posted to Unidata maintained email lists are
recorded in the Unidata inquiry tracking system and made publicly
available through the web.  Users who post to any of the lists we
maintain are reminded to remove any personal information that they
do not want to be made public.


netcdf-java mailing list
netcdf-java@xxxxxxxxxxxxxxxx
For list information or to unsubscribe, visit:
http://www.unidata.ucar.edu/mailing_lists/




http://bsc.es/disclaimer


--
Don Murray
NOAA/ESRL/PSD and CU-CIRES
303-497-3596
http://www.esrl.noaa.gov/psd/people/don.murray/



  • 2018 messages navigation, sorted by:
    1. Thread
    2. Subject
    3. Author
    4. Date
    5. ↑ Table Of Contents
  • Search the netcdf-java archives: