Re: [netcdfgroup] NetCDF4 for Fusion Data

• To: netcdfgroup@xxxxxxxxxxxxxxxx
• Subject: Re: [netcdfgroup] NetCDF4 for Fusion Data
• From: John Storrs <john.storrs@xxxxxxxxxxxx>
• Date: Tue, 20 Jan 2009 16:43:20 +0000

Hi Ed

I've uncovered a couple of problems:

(1) Variables in an explicitly defined group, using the same 'unlimited'
dimension but of different initialized sizes, result in an HDF error when
ncdump is run (without flags) on the generated NetCDF4 file. No problems are
reported when the file is generated (all netcdf call return values are
checked in the usual way). The dimension is defined in the root group. Try
writing data of size S to one variable, and size < S to the next. This error
isn't seen if the variables are all in the root group. In that case, ncdump
fills all variables to the maximum size which I suppose is a feature and not
a bug. An ncdump flag to disable this feature would be useful.

(2) I'm doing tests in C and C++, using the C API in both cases. In some
function prototypes (eg nc_def_dim), char pointers are not defined as const,
causing g++ 4.3 to complain when a string constant argument is used.

Are there any GUI data viewers for NetCDF4 along the lines of hdfview which
cope at least with groups and unlimited dimensions? hdfview itself doesn't
work for me on NetCDF4 files, presumably because it's based on HDF5 1.6.

Regards
John


--
John Storrs, Experiments Dept      e-mail: john.storrs@xxxxxxxxxxxx
Building D3, UKAEA Fusion                               tel: 01235 466338
Culham Science Centre                                    fax: 01235 466379
Abingdon, Oxfordshire OX14 3DB              http://www.fusion.org.uk

• References:
  • [netcdfgroup] NetCDF4 for Fusion Data
    • From: John Storrs