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[netCDF #QLD-285503]: Two netCDF v4.0 Questions

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  • Subject: [netCDF #QLD-285503]: Two netCDF v4.0 Questions
  • Date: Fri, 05 Dec 2008 09:12:39 -0700
Hi Peter,

Yes, the ncgen4 alpha version of the ncgen utility that's in the
4.0.1-beta1 release at

  ftp://ftp.unidata.ucar.edu/pub/netcdf/netcdf-beta.tar.gz

supports unsigned types as well as user-defined types, multiple
unlimited dimensions, attributes of non-primitive types, and other
features of the enhanced data model supported by netCDF-4.  Currently
the -b and -c options for binary netCDF and C program output are
supported, but there is no generation of Fortran source yet.  To build
ncgen4, you must supply the option --enable-ncgen4 to configure on
building.

We will release 4.0.1-beta2 soon, and it will support a few more features,
including special virtual attributes output by ncdump that specify
performance-related features such as compression and chunking.

Note that the ncdump in release 4.0 already supports the new CDL syntax,
and you can see examples of it in some of the ncdump/ref_*.cdl files in
the ncdump directory, used for testing the new features.

The unsigned syntax uses the CDL keywords "ubyte", "ushort", "uint", and
"uint64" for declaring variables, attributes, and compound type members.
When constants of these types are needed to declare variable attributes of
unsigned types, for _FillValue attributes for example, the suffixes "UB",
"US", "U", and "UL" are used.  ncgen4 understands these suffixes in either
lower or upper case.

By the way, in the previous response I said the failure of -k3 and -k4 was a
bug in the 4.0 release, but forgot to point out that bug was only with the
"-c" option for generating C code.  The -k3 and -k4 options should have
worked fine with the -b or -o options for generating binary netCDF-4 files
from CDL.

--Russ




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



Ticket Details
===================
Ticket ID: QLD-285503
Department: Support netCDF
Priority: Normal
Status: Closed