Subject: HDF Newsletter

From: [email-masked] (Shiming Xu)
Date: 11 Mar 1994 00:04:26 GMT

HDF Newsletter 
 
                           March 10, 1994

Contents

1. Introduction
2. Announcement on HDF3.3 release 3
3. The first official release of the HDF Reference Manual V3.3
4. Information about limits in HDF releases
5. ANSI C in future versions
6. Policy on Fortran 90 support for HDF
7. Update on NCSA tools
8. New contributions

Introduction
============

We are trying to start writing the next newsletter
as soon as the previous one has been sent out. We will
build it up over time with paragraphs and will
keep it with file name Newsletter???.draft on ftp
so that people can view it periodically to see
what was up. An .html file is also available on the NCSA ftp server.

Announcement on HDF3.3 Release 3
================================

HDF3.3r3 was officially released on Feb.28. It contains some improvements
in the SD interface, Vdata interface, and fixed a couple of memory
leaks.  Operating systems Windows NT and Solaris are now supported as
well as machines based on the Intel i860.  See ABOUT_3.3r3 for more
details.

A patch was put in HDF/HDF3.3r3/patches/ on March 2 in order to
prevent problems when older applications programs open HDF3.3r3
files. With the latest release, by request, Vdata field names now
are case sensitive.  A patch was added so that the sds interface
doesn't create vdatas with case sensitive names so that existing
applications programs do not have trouble reading the files.

The first official release of the HDF Reference Manual V3.3
===========================================================

Many thanks for the feedback from HDF users on the draft
of HDF Reference Manual V3.3. We have revised the documentation
and its first officail version is now available on the NCSA ftp
server,in subdirectory Documentation/HDF3.3/Ref_Manual/.
The draft was moved to Documentation/HDF3.3/Ref_Manual_draft/ temporarily.
It will be removed from the ftp server on March 1, 1994.

Information about limits in HDF releases
========================================

The current implementation of HDF contains limits on certain aspects of
hdf files. Some of the limits are defined in the library, others are
implied by the number types of parameters which are used in HDF internally.
Recently several users' applications happened to reach one or another limits
which caused various error messages or core dumps. To address this problem,
a section of 'Limits of the current release' was inserted into the ABOUT_3.3r3.
A limits.html file is also available on the www HDF information server.

ANSI C in future versions
=========================

We raised the ANSI C issue in Newsletter12 dated Dec. 23, 1993.
Up to now very few responses have been received. Since it will probably affect
a certain number of HDF users, we are re-posting the section of
'ANSI C in HDF 4.0' of the Newsletter12 below hoping to draw users objections
and comments.

      ANSI C in HDF 4.0
      -----------------
      There has been some discussion among the members of the HDF
      development team about the issue of our next major release (v4.0)
      being primarily targeted towards the use of ANSI C conforming
      compilers.

      We would like to have v4.0 and all further releases of the HDF library
      and utilities be written to only compile with ANSI C compilers. We
      believe this will increase the clarity and maintainability of our
      code.

      In the interests of maintaining backwards compatibility with K&R C
      compilers, we would distribute in the release Peter Deutsch's ansi2knr
      tool which can convert ANSI C code into K&R compliant code. This would
      allow older K&R C compilers continued access to new versions of the
      library.

      Please respond to Quincey Koziol at [email-masked] for future
      correspondence on this issue.

Policy on Fortran 90 support for HDF
====================================

Some user's have asked the NCSA HDF group if we
plan to support Fortran 90 versions of the HDF
APIs. After some discussion, we have determined
that this would not be simple, for several
reasons, including:

   There are significant differences between Fortran 90 and Fortran 77, 
   which we currently do support Fortran 90 compilers are not currently
   implemented on many platforms that HDF is currently supported on
   Support for Fortran 90 should probably involve adding new capabilities 
   to the Fortran interface, such as support for structures and dynamic 
   memory allocation. Such capabilities are desirable, but substantial 
   resources are required to implement them in HDF.

Hence, we have adopted the following policy on Fortran 90 support for HDF:

"The HDF library does not currently support Fortran 90 APIs for any of 
its interfaces. The HDF group has no plans to support Fortran 90 APIs
until a compelling need is observed for such support, Fortran 90 
compilers become available on most platforms that HDF currently supports, 
and sufficient resources can be obtained for implementing Fortran 90 APIs."

Update on NCSA Tools
====================

XDataSlice 2.3 is now available on the NCSA ftp server, in directory:

        /UNIX/XDataSlice/XDS2.3/

XDS2.3 fixes some memory leaks; allows 2 Colormaps (when using the palette 
editor), one for the dicer images and one for the other windows; includes 
more communication support. Read the README file in that directory for 
details about the new features in XDS2.3.

New contributions
=================

HDF3.2r2 was ported to FreeBSD on IBM-PC 386/486.

Pedro Vazquez, [email-masked] ported HDF3.2r2 to FreeBSD 
on IBM-PC 386/486. This HDF port suports all HDF features
under C and almost all under fortran. The library
works with both gnu f77 and f2c/gcc. The library
was used to compile XDataSlice and it's able to
read hdf files created on Suns and IBM as well
create hdf files readable by these machines. There are  no
byte order problems.

The port is in HDF/contrib/HDF3.2r2.FreeBSD.386.486