HDF Newsletter 72

July 11, 2003

To subscribe/unsubscribe to the hdfnews mailing list, please send your
request to ncsalist@ncsa.uiuc.edu with the appropriate command (e.g.
subscribe hdfnews, unsubscribe hdfnews, help) in the *body* of the message.

Release of HDF5-1.6.0

We are pleased to announce the release of HDF5-1.6.0.

HDF5-1.6.0 is now available for download from the NCSA HDF5 home page at:
http://hdf.ncsa.uiuc.edu/HDF5/

The HDF5 documentation is included in the source code and can also be accessed from:
http://hdf.ncsa.uiuc.edu/HDF5/doc/

This is a fully tested release. The configuration features supported in this release can be viewed at:
http://hdf.ncsa.uiuc.edu/HDF5/release/SuppConfigFeats.html

The RELEASE.txt file in the source code contains detailed information about this release:
ftp://ftp.ncsa.uiuc.edu/HDF/HDF5/current/src/unpacked/release_docs/RELEASE.txt

For information on functions that have changed in HDF5-1.6.0, see:
http://hdf.ncsa.uiuc.edu/HDF5/doc/ADGuide/Changes.html

New Features and Changes

The major new features in HDF5-1.6.0 are:

Generic properties to give applications more flexibility and better organization.

The HDF5 properties were redesigned to implement the property list as an object. In addition to the predefined property lists, users can now create or modify their own property lists.

Compact storage layout for datasets. This layout allows small datasets to be stored in the object header, to improve performance.

Redesigned I/O for better performance. The internal design of chunked data I/O has been changed to better handle data caching. Also, the internal design of hyperslab selection has been improved in a variety of ways. Several new hyperslab functions have been added to the API, as well.

New filters:

An external compression filter for szip. Please refer to the following page regarding szip compression and license information:

http://hdf.ncsa.uiuc.edu/HDF5/doc_resource/SZIP/index.html

An internal shuffling filter. The combination of shuffling and compression can be used to improve the data compression ratio.

An internal checksum filter (Fletcher32 Error Detection Code) allows you to check the integrity of an HDF5 file.

The RELEASE.txt file contains more information on these filters.
The addition of space allocation time and value filling time properties.

API calls have been added to set not only the fill value, but also the space allocation and value-filling time for a dataset. These parameters allow the user to control when the library allocates space for data and writes fill values.

Other important changes in HDF5 include:

Added a new API function to get the name of an object using an open ID (hid_t).

The library now correctly reuses space when objects are deleted in the file. This works properly except with datasets that use variable-length datatypes.

Added two new scripts, h5fc and h5c++, for compiling F90 and C++ HDF5 applications.

A new function (H5Fget_obj_count) has been added to retrieve the open IDS for objects in a file.

The h5diff utility has been added for comparing two HDF5 files.

The h5import utility has been added to import ASCII and binary data to an HDF5 file.

Please refer to the RELEASE.txt file in the source code for further details.

Platforms Tested

    AIX 5.1  (32 and 64-bit)      
    Cray T3E sn6606 2.0.6.08   
    Cray SV1 sn9617 10.0.1.2     
    Cray T90IEEE 10.0.1.01y       
    FreeBSD 4.7               
    HP-UX B.11.00        
    IRIX 6.5                     
    IRIX64 6.5 (64 & n32)  
    Linux 2.4.18            
    OSF1 V5.1              
    SunOS 5.7  (Solaris 2.7) (32 and 64-bit) 
    SunOS 5.8  (Solaris 2.8) (32 and 64 bit)         
    TFLOPS r1.0.4 v4.3.3 i386   
    IA-32 Linux 2.4.9           
    IA-64 Linux 2.4.16 ia64    
    Windows 2000 (NT5.0)      
    Windows XP                
    MAC OS X

For compiler information please refer to the following page or to the RELEASE.txt file:
http://hdf.ncsa.uiuc.edu/HDF5/release/platforms5.html

Known Problems

Known problems at release time are listed in the RELEASE.txt file that comes with the source code.
Further information on known problems can be found on the following page:
http://hdf.ncsa.uiuc.edu/HDF5/release/known_problems5.html

SZIP License Information

This is the first release for which we support SZIP compression in HDF5.

For SZIP license information, as well as other SZIP information, please refer to the following page:
http://hdf.ncsa.uiuc.edu/HDF5/doc_resource/SZIP/index.html

Release of H4 to H5 Conversion Library Version 1.1

A new release of the H4 to H5 Conversion Library, version 1.1, is now available for download from the following page:
http://hdf.ncsa.uiuc.edu/h4toh5/

This version was tested with HDF5-1.6.0. Pre-compiled binaries are not included with this release.

Release of HDF5 High Level APIs Version 1.2.0

A new release of the HDF5 High Level APIs, version 1.2.0, is now available for download from the following page:
a href="http://hdf.ncsa.uiuc.edu/HDF5/hdf5_hl/">http://hdf.ncsa.uiuc.edu/HDF5/hdf5_hl/