
                          HDF 4.2 Release 0
                           December 2003

INTRODUCTION

This document describes the differences between HDF 4.1r5 and
HDF 4.2r0.  It is written for people who are familiar with
previous releases of HDF and wish to migrate to HDF 4.2r0

The HDF 4.2r0 documentation can be found on the NCSA ftp server 
(ftp.ncsa.uiuc.edu) in the directory:

     ftp://hdf.ncsa.uiuc.edu/HDF/Documentation/

First-time HDF users are encouraged to read the FAQ in this
release for more information about HDF.  Users can also look
at the home page for HDF at:

     http://hdf.ncsa.uiuc.edu/

If you have any questions or comments, please send them to:

     hdfhelp@ncsa.uiuc.edu

CONTENTS

- New Features and Changes
- Support for new platforms
- Bugs fixed since HDF4.1r5
- Documentation
- Platforms Tested
- Known problems

New Features and Changes:
========================

o ZLIB and JPEG libraries were removed from the HDF4 distribution source.
  Please read INSTALL in the top HDF4 directory for instructions
  how to build HDF4 Library and applications.

o HDF4 has an optional SZIP compression; please refer to the INSTALL 
  file for instructions how to build with/without the SZIP Library.
  SZIP in HDF4 is free for non-commercial use; 
  see http://hdf.ncsa.uiuc.edu/doc_resource/SZIP/Commercial_szip.html 
  for information regarding commercial use. 

  For more information about SZIP compression
  see http://hdf.ncsa.uiuc.edu/doc_resource/SZIP/ and 
  the "HDF4 Reference Manual" entries for the GRsetcompress and 
  SDsetcompress functions. 

o The following new tools have been added

      hrepack
      hdiff
      hdfimport

  See "HDF4 Reference Manual" in the HDF 4.2r0 documentation set for more
  information.

o Helper scripts to facilitate HDF4 installation and compilation were added:
  
      h4cc   - to compile C application with the HDF4 Libraries
      h4fc   - to compiler Fortran applications with the HDF4 Libraries
      h4redeploy - to fix binary installation

  See "HDF4 Reference Manual" in the HDF 4.2r0 documentation set for more
  information.

Support for new platforms 
=========================

o HDF4 was ported to the following platforms

      AIX 5.1 64-bit version
      MacOSX
      Linux 2.4 RH8 and RH9 
      Linux 2.4 RH8 64-bit, SuSE 64-bit
      Linux 2.4 ia64


Bugs fixed since HDF4.1r5
=========================

1. "hdp dumpgr" and "hdp dumpsds" have two new options:
        -g to suppress the data of global (or file) attributes
        -l to suppress the data of local attributes

2. The problem where hdp failed on very long file name has been
   fixed. (bug #693)

3. The problem where VSinquire failed when being called on a vdata
   that has no fields defined, has been fixed. (bug #626)

4. A user attempted to change the values of VGNAMELENMAX and VSNAMELENMAX
   to 256 for her own use, but the hdp output showed that the change was
   not in effect.  This problem is now fixed. (bug #606)

5. hdp dumpvg failed sometimes when reading a file that has a vgroup 
   being inserted into another.  This has been fixed. (bug #477)

6. fp2hdf when used with -p option did the opposite of what it was supposed
   to do with palette files. This problem is now fixed. (bug #800). However
   the utility hdfimport should be used in the future instead of fp2hdf.

7. hdf2gif failed when a user tried it on JPEG compressed images. (Bug #601).
   The problem is now fixed. An error message is displayed if the image is not
   8-bit. If the image is 24-bit, the message suggests using hdf2jpeg.

8. ncdump failed to read NetCDF files 3.5 when there were more than one variable
   with unlimited dimensions. Fixed.

9. NetCDF part of the HDF4 Library was not ported to Compaq True64 system. Fixed.

10. The hdp commands dumpsds, dumpgr, dumpvd, and dumpvg now display an 
    informative message when a non-HDF file is given as input. (Bug #817)

11. The compilation warnings and error on the macro HDFclose are fixed.
    (Bug #818)

Documentation
==============

    Entries for new utilities hdiff, hrepack, hdfimport and helper
    scripts h4cc, h4fc, and h4redeply were added to the Reference Manual.

Platforms Tested
================

HDF 4.2 Release 0 has been tested on the following platforms:

    AIX 5.1  (32 and 64-bit)      xlc 6.0.0.2
                                  xlf 8.1.0.3
    Cray T3E sn6606 2.0.6.08      Cray Standard C Version 6.6.0.2
                                  Cray Fortran Version 3.6.0.2
    Cray SV1 sn9617 10.0.1.2      Cray Standard C Version 6.6.0.2
                                  Cray Fortran Version 3.6.0.2
    FreeBSD 4.9                   gcc 2.95.4
                                  g++ 2.95.4
    HP-UX B.11.00                 HP C  HP92453-01 A.11.01.20 
                                  HP F90 v2.4
                                  HP ANSI C++ B3910B A.03.13
    IRIX64 6.5 (64 & n32)         MIPSpro cc 7.3.1.3m
                                  F90 MIPSpro 7.3.1.3m (64 only)
    Linux 2.4.20-20.7 (RH8)       gcc 3.3.1
                                  Intel(R) C++ Version 7.1
                                  Intel(R) Fortran Compiler Version 7.1
    Linux 2.4.20-20.9 (RH9)       gcc 3.2.2
    Linux 2.4.21-2.9.5ws (64-bit) gcc version 3.2.3 20030502 (Red Hat Linux 3.2.3-16)
                                  g77 based on gcc version 3.2.3
    Linux 2.4.19-SMP #1           gcc version 3.3.2 (SuSE Linux)
                                  gcc version 3.3.2
    OSF1 V5.1                     Compaq C V6.4-014
				  Compaq Fortran V5.5-1877
    SunOS 5.7(32 and 64 bit)      WorkShop Compilers 5.0 98/12/15 C 5.0
     (Solaris 2.7)                WorkShop Compilers 5.0 98/10/25 
                                  FORTRAN 77 5.0
                                  gcc 3.2.2
                                  g77 GNU Fortran (GCC 3.2.2) 3.2.2 
    SunOS 5.8(32 and 64 bit)      Sun WorkShop 6 update 2 C 5.3
     (Solaris 2.8)                Sun WorkShop 6 update 2 Fortran 77 5.3 

    IA-32 Linux 2.4.9             gcc 2.96
                                  Intel(R) C++ Version 7.0
                                  Intel(R) Fortran Compiler Version 7.0
                                  
    IA-64 Linux 2.4.16 ia64       Intel(R) C++ Version 7.0
                                  Intel(R) Fortran Compiler Version 7.0
    IA-64 Linux 2.4.19-SMP        Intel(R) C++  Version 7.1
                                  Intel(R) Fortran Compiler Version 7.1
                                  gcc 3.2
                                  g77 GNU Fortran (GCC 3.2) 3.2
    Windows 2000 (NT5.0)          MSVC++ 6.0
                                  DEC Visual Fortran 6.0
                                  Intel C and F90 compilers version 7.1
    Windows XP                    MSVC++.NET
    MAC OS X                      Darwin 6.8
                                  gcc Apple Computer, Inc. GCC 
                                  version 1175, based on gcc version 3.1
                                  

Known problems
==============

o  SZIP Library is not available for Crays SV1 and T3E
   Fortran APIs do not support SZIP compression.

o  NetCDF tests nctest (C) and ftest (Fortran) fail to read from NetCDF 3.5 files

o  On Linux RH8 64-bit SZIP tests fail if library is compiled in production
   mode. All tests pass in the debug mode.

o  This release doesn't support VMS system.

o  On Linux with gcc compilers Fortran NetCDF APIs cannot read attributes, variables,
   and dimensions when name contain spaces.

o  HDF4 Library cannot be built with PGI compilers.

o  N-Bit compression is not supported with Fortran APIs.

o  Using both fill-value and compression on SD datasets doesn't work.
