This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.
Hi Amanda, > I am a researcher at meteo-france and i am contacting you to get some > advice about generating netcdf files. I would like to generate a netcdf > output file containing at the same time a map of objects which have > single value attributes and also an attribute which is a array with a > variable length. Is it possible to generate this kind of structure? If > yes, how can I do it? By "map of objects which have single value attributes" I'm assuming you mean a collection of objects, possibly of different types, that each have a named attribute of the same name and type. If each of the objects is represented as a netCDF variable accessible by its name, then such a data type can be represented in a netCDF file as a collection of netCDF variables. However, this is not a very convenient representation, as the objects each must have distinct names, and cannot be accessed by their attribute values, for example. If you are using netCDF-3 with its simple data model and "classic" data format, you won't be able to easily represent either of those kinds of data structures. However, using the netCDF-4 enhanced data model, with its support for user-defined types, variable-length types, and groups, I think it is possible to represent what you want. Alternatively, you may want to also look at HDF5, which supports a "reference" type. An array of references pointing to other data objects may but what you want for the map data structure, and netCDF-4 does not include support for HDF5 references. --Russ Russ Rew UCAR Unidata Program address@hidden http://www.unidata.ucar.edu Ticket Details =================== Ticket ID: XFU-202199 Department: Support netCDF Priority: Normal Status: Closed