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                              Newsletter #27
                              October 23, 1997
 
CONTENTS
 
HDF5 Prototype Release 
HDF 4.1r1 for T3E                          *******************************
HDF Tutorial                               * Visit the HDF home page     *
                                           * for up-to-date information  *
                                           * on HDF:                     *
                                           *   http://hdf.ncsa.uiuc.edu/ *
                                           *******************************
 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

HDF5 Prototype Release
======================

The HDF5 Prototype release is now available, and can be downloaded
from the HDF ftp server (hdf.ncsa.uiuc.edu): 
     /pub/outgoing/koziol/hdf5.tar.gz

The documentation is included with the release, and is also accessible
from the URL:
     http://hdf.ncsa.uiuc.edu/nra/BigHDF/

This release is intended primarily as a proof of concept and as a method 
of familiarizing users with the intended functionality. 

When complete, HDF5 will include the following features:

 - A new file format designed to address some of the deficiencies
   of the current version of HDF, particularly the need to store
   larger files and more objects per file.

 - A simpler, more comprehensive data model that includes only two
   basic structures: a multi-dimensional array of record structures,
   and a grouping structure.

 - A simpler, better-engineered library, with improved support for
   parallel I/O, threads, and other requirements imposed by
   modern systems and applications.

 - A new API.

Limitations of the current prototype are:
 - Multiple datasets may be created/read/written in an HDF5 file, but
   access must be as an entire dataset, i.e. no slab/slice/subset code is
   implemented yet.  The datasets must also be homogeneous, orthogonal
   datasets, similar to the datasets which can be created in the
   HDF4 "SD" interface.  Reducing these restrictions will be a major
   effort of further development on the library.

 - Datasets can be located in a hierarchy of groups in the file, however
   user-level features for transitioning through the groups are not
   implemented in this release.  Each dataset must be accessed through
   its full "pathname" in the file, ie. "/foo/bar/dataset1",
   "/foo/bar/dataset2", "/foo/data"
 
HDF5 has been tested on the following Unix platforms:
    Linux, FreeBSD, IRIX, Solaris and Digital Unix

Machines which do not have IEEE floating-point representation or non 
big- or little-endian memory representations are not supported in 
this release. Most other machines should work correctly.


HDF 4.1r1 for T3E
=================

We have made changes to the HDF 4.1r1 release to support the T3E
platform.  This software did not go through a full QA cycle and
is considered to be beta quality.  

The netCDF (ncxxx) interfaces and ncdump, ncgen, and hdp do not 
work properly in this T3E release.  

The source code and pre-compiled HDF 4.1r1 software for the T3E can 
be found on the NCSA ftp server (ftp.ncsa.uiuc.edu) in the directory:
   /HDF/HDF_Current/bin/t3e/

If you encounter any problems, please contact the HDF Helpdesk
(hdfhelp@ncsa.uiuc.edu).


HDF Tutorial
============

We have made a first cut of an HDF Tutorial.  It includes the
SD, Vdata, Vgroup, multi-file annotations (AN), and GR interfaces.

You can access it from the HDF home page under:
  "Information about HDF -> Tutorials, Lectures, Examples ..."
(http://hdf.ncsa.uiuc.edu/tutslects.html)

If you have ideas for making it better, feel free to contact
the HDF Helpdesk (hdfhelp@ncsa.uiuc.edu).