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Vicent, On 21/12/16 08:58, Vincent THIERION wrote:
Hello,By reading different posts on tiled aggregation (i.e. aggregation along longitude and latitude dimensions), such as :* http://www.unidata.ucar.edu/mailing_lists/archives/thredds/2011/msg00270.html * http://www.unidata.ucar.edu/mailing_lists/archives/thredds/2013/msg00500.htmlbetter than "labor-intensive" NCML implementation it looks like this capability is handled by GridDataset and the Netcdf SubsetService object : http://www.unidata.ucar.edu/mailing_lists/archives/netcdfgroup/2011/msg00133.html, only accessible with java library while I work with the python library.All these posts are quite old and I ask me what the better way is now ? Maybe stich all the netcdf files in one NetCDF before serve on TDS ?
The tiled aggregation it's one problem and subsetting is different one. To aggregate on non-outer dimensions the only existing in netcdf-java it's tiled one. Never released with full support but it's there and working. The most common cases are aggregation on outer-dimensions or non-existing ones.
This aggregation could be made using netcdf-java ncml and serving, using TDS, as opendap/netcdfsubsetting endpoints.
To subsetting dataset (aggregated on non-aggregated) relies on tool/client side. Python pyDap or Netcd4 packages are able to access opendap services to subsetting purposes. Please note that the Netcdf4 package needs to access to netcdf library compiled with opendap reading capabilities.
Only specific implementation like x-array python packages has some multifile aggregation
http://xarray.pydata.org/en/stable/generated/xarray.open_mfdataset.html#xarray.open_mfdatasetNcML aggregation is general specification but only netcdf-java has full support of it. Some other implemetations exist:
https://github.com/axiom-data-science/pyncml or the BES implemetation: http://docs.opendap.org/index.php/BES_-_Modules_-_NcML_Module But neither of them supports Tiled aggregation. Regards Antonio S. Cofiño
Thank you for your useful feedbacks -- ------------------------------- Vincent THIERION Ingénieur de recherche - THEIA - CES OSO vincent.thierion [at] cesbio.cnes.fr vincent.thierion [at] inra.fr CESBIO (Bureau 123) (UMR 5126 CNRS/CNES/UPS/IRD) Bpi 2801 18 Av. Edouard BELIN 31401 TOULOUSE CEDEX 9 INRA - Toulouse - Dynafor (UMR 1201 INRA/INP-ENSAT/INP-EI Purpan) 24 chemin de Borde-Rouge Auzeville BP 52627 31326 CASTANET-TOLOSAN CEDEX ------------------------------- _______________________________________________ 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. thredds mailing list thredds@xxxxxxxxxxxxxxxx For list information or to unsubscribe, visit: http://www.unidata.ucar.edu/mailing_lists/
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