[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[netCDF #GGJ-180191]: c interface ncredef destroys netcdf character of file

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 Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated.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.

  • Subject: [netCDF #GGJ-180191]: c interface ncredef destroys netcdf character of file
  • Date: Thu, 14 May 2009 15:51:32 -0600
Hi Rita,

Thanks for sending the header file date.  From this, it looks like you have a 
version
before netCDF-3.5.0 installed (from late 2000), because that version mentions 
the
following bug fixes in its RELEASE_NOTES:

 * Fixed a number of bugs related to attempts to support shrinking the
   header in netCDF files when attributes are rewritten or
   deleted. Also fixed the problem that nc__endef() did not work as
   intended in reserving extra space in the file header, since the
   extra space would be compacted again on calling nc_close().

 * Fixed the "redef bug" that occurred when nc_enddef() or nf_enddef()
   is called after nc_redef() or nf_redef(), the file is growing such
   that the new beginning of a record variable is in the next "chunk",
   and the size of at least one record variable exceeds the chunk size
   (see netcdf.3 man page for a description of this tuning parameter
   and how to set it). This bug resulted in corruption of some values
   in other variables than the one being added.

I don't see any other bugs fixed in this version that seem relevant to
the problem you are seeing, although it's also hard to see why the bug
occurs only in the C but not in the Fortran API, because the Fortran
API is just a thin layer that calls the C API.

In any case, I recommend that you update to a more recrnt version of
netCDF.  If you need guidance deciding on what version to install, see
the FAQ questions and answers here:

  http://www.unidata.ucar.edu/netcdf/docs/faq.html#fv3

--Russ


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



Ticket Details
===================
Ticket ID: GGJ-180191
Department: Support netCDF
Priority: Normal
Status: Closed