Re: Basic Issues using netcdf service & aggregation

[John Caron <caron@xxxxxxxxxxxxxxxx>]

Hi Apurv:

1. you need to enable the NetCDF Subset Service in the config file, see:

 http://www.unidata.ucar.edu/projects/THREDDS/tech/reference/ThreddsConfigXMLFile.html

2. In this element:

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

You havent added any files, you cant use a datasetScan element here. You want something like 

<dataset name="Test all files in a directory" ID="testUnion" urlPath="satellite/union.nc"

   <metadata inherited="true">
     <serviceName>thisNETCDF</serviceName>
     <dataFormat>NetCDF</dataFormat>
   </metadata>

   <netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
    <aggregation type="union">
      <scan location="/data/ldm/pub/native/satellite/3.9/WEST-CONUS_4km/" suffix=".nc" />
    </aggregation>
   </netcdf>

 </dataset>


see:

 http://www.unidata.ucar.edu/projects/THREDDS/tech/tutorial/NcML.htm

3. thanks for letting me know who you work for

4. in the future, send these questions to support-thredds@xxxxxxxxxxxxxxxx


good luck!





Apurv Bhartia wrote:
> Hi John,
>
> I have basically started with THREDDS server and netCDF a couple of days 
> back. I have had a look at the documentation provided but cannot figure 
> this out.
> Two Issues -
> 1) I am trying to get the dataset use the netcdf service, but it fails 
> giving me the error that 'service not found'.
>
> Below is the code -
> <?xml version="1.0" encoding="UTF-8"?>
> <catalog name="THREDDS Server Default Catalog : You must change this to 
> fit your server!"
>         xmlns=" 
> http://www.unidata.ucar.edu/namespaces/thredds/InvCatalog/v1.0";
>         xmlns:xlink="http://www.w3.org/1999/xlink 
> <http://www.w3.org/1999/xlink>">
>
>   <service name="thisDODS" serviceType="OpenDAP" base="/thredds/dodsC/" />
>   <service name="thisNETCDF" serviceType="NetcdfServer" 
> base="/thredds/ncServer/" />
>   <datasetRoot path="test" location="content/testdata/"/>
>   <dataset name="Test Single Dataset" ID="testDataset" 
> serviceName="thisNETCDF"
>            urlPath="test/testData.nc"/>
>   <datasetScan name="Test all files in a directory" ID="testDatasetScan"
>                path="testAll" location="content/testdata">
>     <metadata inherited="true">
>       <serviceName>thisNETCDF</serviceName>
>     <dataFormat>NetCDF</dataFormat>
>     </metadata>
>
>     <filter>
>       <include wildcard="*.nc"/>
>     </filter>
>     <netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
>     <aggregation type="union"/>
> </netcdf>
>   </datasetScan>
>   <catalogRef xlink:title="Test Enhanced Catalog" 
> xlink:href="enhancedCatalog.xml" name=""/>
> </catalog>
>
>
>
> 2) Further, I have a few doubts regarding aggregation. I am trying to 
> get the aggregation thing going. Basically, I'd like to take files from 
> a specified directory and aggregate them (type = "union")
>
> <?xml version="1.0" encoding="UTF-8"?>
> <catalog name="THREDDS Server Default Catalog : You must change this to 
> fit your server!"
>         xmlns=" 
> http://www.unidata.ucar.edu/namespaces/thredds/InvCatalog/v1.0";
>         xmlns:xlink="http://www.w3.org/1999/xlink";>
>
>   <service name="thisDODS" serviceType="OpenDAP" base="/thredds/dodsC/" />
>   <service name="thisNETCDF" serviceType="NetcdfServer" 
> base="/thredds/ncServer/" />
>  <datasetRoot path="test" location="content/testdata/"/>
>   <dataset name="Aggregate all files in a directory" path="test">   
>      <serviceName>thisDODS</serviceName>
>      <netcdf 
> xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
>     <aggregation dimName = "refTime" type="joinExisting">
>         <scan location="content/testdata/" 
> suffix=".nc"/>                                                                                        
> // this is the location,and aggregate all files ending with .nc
>     </aggregation>
>     </netcdf>
>   </dataset>
> </catalog>
>
> Objective is to take files from /content/testdata directory and 
> aggregate them. It would be great if you can tell me where I am goofing 
> up and how to go about it.
>
> Thanks a lot,
> -Apurv