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Hi Antonio- On 11/6/13 10:02 AM, "Antonio S. Cofiño" wrote:
Just a warning. The dimension order is not trivial for the CDM. For the time dimesion it could be has a different meaning. In my example float tas(ensemble=5, time1=121, height=1, lat=126, lon=201); It would be interpreted (implicitly) as Time coordinate axis (forecast time). And in your example: float Total_precipitation(time=1, ens=11, lat=27, lon=51); It would be interpreted as RunTime coordinate axis. The CDM has the concept of 2D time coordinates, and the order for dimensions are non-trivial.
Good point. However, in my case, I use the CF axis attribute (T) on my time coordinate which explicitly labels it as the time coordinate instead of the runtime coordinate (which doesn't have support in CF). So, I should qualify my earlier statement that the CDM doesn't care of the order as long as you identify the coordinate axes using the CF or CDM standards (axis or _CoordinateAxisType attributes). The canonical order for the axes in the CDM is:
(runtime, time, ensemble, z, y, x) (see ucar.nc2.constants.AxisType) Looking at the source, at one point, it was: (runtime, ensemble, time, z, y, x)So it might be that since time implicitly now comes before ensemble, my order might work, even without the axis identifier. But it is good practice to identify the axes explicitly.
Don
-- Antonio S. Cofiño Grupo de Meteorología de Santander Dep. de Matemática Aplicada y Ciencias de la Computación Universidad de Cantabria http://www.meteo.unican.es El 06/11/2013 16:24, Don Murray (NOAA Affiliate) escribió:All- This provides an example of the different ways that an ensemble dimension can be used and that the CDM can handle. For Antonio's example, the dimension ordering is: float tas(ensemble=5, time1=121, height=1, lat=126, lon=201); :_CoordinateAxes = "ensemble time1 height lat lon "; :standard_name = "air_temperature"; :long_name = "Surface air temperature"; :units = "Celsius"; with ensemble as the leftmost dimension In the ensemble files I generate, they are: float Total_precipitation(time=1, ens=11, lat=27, lon=51); :_FillValue = 9999.0f; // float :units = "kg m-2"; :long_name = "Total_precipitation_Accumulation (Accumulation for Mixed Intervals) @ surface"; I put time in the leftmost dimension. The nice thing is that the CDM does not care! You can structure it according to your needs. Don On 11/5/13 12:59 PM, Cofiño Gonzalez, Antonio Santiago wrote:Roland, This is an example with Ensemble coordinate axis http://www.meteo.unican.es/thredds/catalog/WRFUC/2013110412/catalog.html?dataset=OPERWRF12DatasetScan/2013110412/oper_gfs_mgrama_2013110412_d02.ncml Antonio S. Cofiño Santander Meteorology Group University of Cantabria El 05/11/2013, a las 16:45, "Roland Schweitzer - NOAA Affiliate" <roland.schweitzer@xxxxxxxx <mailto:roland.schweitzer@xxxxxxxx>> escribió:Hi, I see hints in the Java netCDF API that it can understand a grid that has an ensemble axis. What's not clear to me is how one constructs a netCDF data source (either in the file or via some sort of TDS aggregation) that represents the ensemble. The CF conventions document doesn't seem say anything about ensembles. Google is failing me, can anybody offer some examples or documentation links for data sources with an ensemble axis? Thanks, Roland _______________________________________________ netcdf-java mailing list netcdf-java@xxxxxxxxxxxxxxxx <mailto:netcdf-java@xxxxxxxxxxxxxxxx> For list information or to unsubscribe, visit: http://www.unidata.ucar.edu/mailing_lists/_______________________________________________ netcdf-java mailing list netcdf-java@xxxxxxxxxxxxxxxx For list information or to unsubscribe, visit: http://www.unidata.ucar.edu/mailing_lists/
-- Don Murray NOAA/ESRL/PSD and CIRES 303-497-3596 http://www.esrl.noaa.gov/psd/people/don.murray/
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