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

[netCDF #PHH-929360]: Import to Mathematica

Hi Jim,

> Has the netCDF file format changed significantly between version 3
> and version 3.6.2?

No, the "classic" netCDF format that is the default when creating a
file with any version of netCDF, including netCDF 3.6.2, has not
changed since version 1 of the netCDF library, in 1989.

However, netCDF 3.6.0 added a new variant of the netCDF format with
64-bit offsets to support larger file sizes.  To create files in this
64-bit offset variant of netCDF, the creator would have to use a
non-default flag on creation.  To determine characteristics of the
netCDF file you have, see the answer to the FAQ "How can I tell if a
netCDF file uses the classic format or new 64-bit offset format?" at

  http://www.unidata.ucar.edu/netcdf/docs/faq.html#Large%20File%20Support5

All versions of netCDF since 3.6.0 read either version of the format
transparently, without the user having to know which variant is used.
So of Mathemeatica were built with netCDF version 3.5.1 or earlier
(released in February 2004), it would not be able to read a 64-bit
offset variant netCDF file.

Recently another format variant was added with the release of
netCDF-4, but the "classic" netCDF format is still the default for
files created with that new library version.  Very few users are
making use of the new netCDF-4 format variant yet, but you could ask
the source of the data whether they have given you netCDF-4 data.
It's unlikely that Mathematica has been built with netCDF-4 yet, as
the 4.0 release is very new and may not be mature enough for most
commercial packages.

--Russ

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



Ticket Details
===================
Ticket ID: PHH-929360
Department: Support netCDF
Priority: Normal
Status: Closed