[netcdf-java] Aggregating NetCDF files programmatically

Hi all,

I am looking into ways of aggregating NetCDF files programmatically for a new version of ncWMS. The aim is to allow expressions such as "*.nc" to result in a single dataset, so long as all NetCDF files share the same variables/dimensions and differ only in the values on their time axes.

I can do this by writing an NcML file, but this is a bit of a hack, and leaves files around. We previously did this by manually keeping track of which time steps appeared in which files, but this doesn't easily fit with our new data model, and seems unnecessary when there are several Aggregation objects in the NetCDF-Java libraries which should be able to do the job for us.

Searching lead me to this message on the list:


but unfortunately there were no responses. I was able to use the AggregationUtil class from that post to read the correct metadata, but like the person who posted I run into trouble when trying to actually read the data. I get a slightly different stack trace, which starts:

java.io.IOException: BAD: missing spi: analysed_sst
    at ucar.nc2.NetcdfFile.readData(NetcdfFile.java:1753)
    at ucar.nc2.Variable.reallyRead(Variable.java:850)

and is then the same as in the other post.

I would be very grateful if anyone could suggest a way of making aggregation work programatically, either with an adaptation of the above method or something completely new.

Best Regards,

Guy Griffiths
Reading eScience Centre

  • 2013 messages navigation, sorted by:
    1. Thread
    2. Subject
    3. Author
    4. Date
    5. ↑ Table Of Contents
  • Search the netcdf-java archives: