[netcdf-java] NcML aggregation across both variables and time dimension

[John Caron]

Hi Jon:

You need one NcML file with nested netcdf elements. The problem is that you cant do a scan on these, you have to list them explicitly, eg:

<netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2">

  <aggregation dimName="time" type="joinExisting">

  <netcdf>
   <aggregation type="union">
    <netcdf location="file:C:/test/path/temperature_20080101.nc" />     
    <netcdf location="file:C:/test/path/salinity_20080101.nc" />
   </aggregation> 
  </netcdf>

  <netcdf>
   <aggregation type="union">
    <netcdf location="file:C:/test/path/temperature_20080102.nc" />     
    <netcdf location="file:C:/test/path/salinity_20080102.nc" />
   </aggregation>
  </netcdf> 

  </aggregation> 

</netcdf>


Jon Blower wrote:
> Hi all,
> 
> I have an ocean modelling dataset in which different variables are
> stored in different files.  Also, there is one data file per timestep
> for each variable.  So my filesystem looks like this:
> 
> temperature_20080101.nc
> salinity_20080101.nc
> temperature_20080102.nc
> salinity_20080102.nc
> 
> I would like to construct an NcML file that aggregates all these files
> into a single dataset but am having trouble.  Can I "union" the
> variables together and then do a "joinExisting" on the union to
> aggregate on the time dimension?  Do I need more than one NcML file
> perhaps, with one file referencing the other?
> 
> Thanks, Jon
>