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[netCDF #PFR-895418]: NetCDF METADATA question

Hi Lulin,

> I used NetCDF sometimes ago. I understood that the NetCDF is very good
> for gridded array style data. Now we have a project which mainly deals
> with meta data. The data are discrete. All data are represented as
> strings. The data are like catalog style. Will NetCDF store those kind
> data easily and efficiently? Does NetCDF have Java Interface to handle
> those kind data?

The newer netCDF-4 data model has support for a "string" data type, so would
be better than the older netCDF-3 "classic" data model, which uses character
arrays instead of real variable-length strings.  So, for example, with the
netCDF-4 data model, you could store an array of strings of different lengths
in a single netCDF variable.

There are some conventions for storing discrete observational data using 
netCDF-3, but you would need to decide whether those conventions are adequate
for your data:

  http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.6/ch09.html

On the other hand, the enhanced netCDF-4 data model is not yet as well 
supported 
by other third-party software for analysis and visualization as the netCDF-3
classic data model, so there are tradeoffs.  Also, depending on what you want to
do with the data, you may find that netCDF provides relatively low-level support
for some operations with strings.  For example, the library doesn't support
efficient content-based indexing or searching in large volumes of string data.

There is a netCDF-Java library, which adds more support for coordinate systems
and other formats than the C-based netCDF libraries:

  http://www.unidata.ucar.edu/software/netcdf-java/

--Russ

Russ Rew                                         UCAR Unidata Program
address@hidden                      http://www.unidata.ucar.edu



Ticket Details
===================
Ticket ID: PFR-895418
Department: Support netCDF
Priority: Normal
Status: Closed