-------------------------------------------------------------------------- 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. -------------------------------------------------------------------------- Newsletter #37 September 18, 1998 CONTENTS ******************************* Beta release of HDF5 version 1.1.0 * Visit the HDF home page * - Changes Since the Second Alpha * for up-to-date information * - Changes Since the First Alpha * on HDF: * - Parallel HDF5 Changes * http://hdf.ncsa.uiuc.edu/ * - Platforms Supported ******************************* - Release Information for Parallel HDF5 HCR Tools Release 2.0v1.2 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Beta release of HDF5 version 1.1.0 ================================== The HDF5 beta release version 1.1.0 is now available. The release distribution is located at: ftp://hdf.ncsa.uiuc.edu/pub/dist/HDF5/ The web-site for HDF5 is located at: http://hdf.ncsa.uiuc.edu/HDF5/ Changes Since the Second Alpha ------------------------------ * Strided hyperslab selections in dataspaces are now working. * The compression API has been replaced with a more general filter API. See Filters in the User's Guide for details. * Alpha-quality 2d ragged arrays are implemented as a layer built on top of other hdf5 objects. The API and storage format will almost certainly change. * More debugging support has been added including API tracing. See Debugging in the User's Guide. * C and Fortran style 8-bit fixed-length character string types are supported with space or null padding or null termination and translations between them. * The function H5Fflush() has been added to write all cached data immediately to the file. * Datasets maintain a modification time which can be retrieved with H5Gstat(). * The h5ls tool can display much more information, including all the values of a dataset. Changes Since the First Alpha ----------------------------- * Two of the packages have been renamed. The data space API has been renamed from `H5P' to `H5S' and the property list (template) API has been renamed from `H5C' to `H5P'. * The new attribute API `H5A' has been added. An attribute is a small dataset which can be attached to some other object (for instance, a 4x4 transformation matrix attached to a 3-dimensional dataset, or an English abstract attached to a group). * The error handling API `H5E' has been completed. By default, when an API function returns failure an error stack is displayed on the standard error stream. H5Eset_auto() controls the automatic printing, and the H5E_BEGIN_TRY/H5E_END_TRY macros can temporarily disable the automatic error printing. * Support for large files and datasets (>2GB) has been added. There is an html document that describes how it works. Some of the types for function arguments have changed to support this: all arguments pertaining to sizes of memory objects are `size_t' and all arguments pertaining to file sizes are `hsize_t'. * More data type conversions have been added although none of them are fine tuned for performance. There are new converters from integer to integer and float to float, but not between integers and floating points. A bug has been fixed in the converter between compound types. * The numbered types have been removed from the API: int8, uint8, int16, uint16, int32, uint32, int64, uint64, float32, and float64. Use standard C types instead. Similarly, the numbered types were removed from the H5T_NATIVE_* architecture; use unnumbered types which correspond to the standard C types like H5T_NATIVE_INT. * More debugging support was added. If tracing is enabled at configuration time (the default) and the HDF5_TRACE environment variable is set to a file descriptor then all API calls will emit the function name, argument names and values, and return value on that file number. There is an html document that describes this. If appropriate debugging options are enabled at configuration time, some packages will display performance information on stderr. * Data types can be stored in the file as independent objects and multiple datasets can share a data type. * The raw data I/O stream has been implemented and the application can control meta and raw data caches, so I/O performance should be improved from the first alpha release. * Group and attribute query functions have been implemented so it is now possible to find out the contents of a file with no prior knowledge. * External raw data storage allows datasets to be written by other applications or I/O libraries and described and accessed through HDF5. * Hard and soft (symbolic) links are implemented which allow groups to share objects. Dangling and recursive symbolic links are supported. * User-defined data compression is implemented although we may generalize the interface to allow arbitrary user-defined filters which can be used for compression, checksums, encryption, performance monitoring, etc. The publicly-available `deflate' method is predefined if the GNU libz.a can be found at configuration time. * The configuration scripts have been modified to make it easier to build debugging vs. production versions of the library. * The library automatically checks that the application was compiled with the correct version of header files. Parallel HDF5 Changes --------------------- * Parallel support has been added for fixed dimension datasets with contiguous or chunked storage. Also, support has been added for unlimited dimension datasets which must use chunk storage. When a dataset is extended in a PHDF5 file, all processes that open the file must collectively call H5Dextend with identical new dimension sizes. No parallel support is included for compressed datasets. * Collective data transfer for H5Dread/H5Dwrite has been added. For now, this only includes collective access support for fixed dimension datasets with contiguous storage. * H5Pset_mpi and H5Pget_mpi no longer have the access_mode argument. It is taken over by the data-transfer property list of H5Dread/H5Dwrite. * New functions H5Pset_xfer and H5Pget_xfer have been added to handle the specification of an independent or collective data transfer_mode in the dataset transfer properties list. The properties list can be used to specify data transfer mode in the H5Dwrite and H5Dread function calls. Platforms Supported ------------------- This release has been tested on UNIX platforms only; specifically: Linux, FreedBSD, IRIX, Solaris & Dec UNIX. Release Information for Parallel HDF5 ------------------------------------- * Current release supports independent access to fixed dimension datasets only. * The comm and info arguments of H5Cset_mpi are not used. All parallel I/O are done via MPI_COMM_WORLD. Access_mode for H5Cset_mpi can be H5ACC_INDEPENDENT only. * This release of parallel HDF5 has been tested on IBM SP2 and SGI Origin 2000 systems. It uses the ROMIO version of MPIO interface for parallel I/O supports. * Useful URL's. Parallel HDF webpage: "http://hdf.ncsa.uiuc.edu/Parallel_HDF/" ROMIO webpage: "http://www.mcs.anl.gov/home/thakur/romio/" * Some to-do items for future releases support for Intel Teraflop platform. support for unlimited dimension datasets. support for file access via a communicator besides MPI_COMM_WORLD. support for collective access to datasets. support for independent create/open of datasets. HCR Tools Release 2.0v1.2 ========================= HDF Configuration Record (HCR) Tools Release 2.0v1.2 is freely avilable for public access. HCR is a tools suite that provides an easy interface to create, modify and access HDF-EOS files. This release has been upgraded to work with the latest official releases of the HDF-EOS library (2.3v1.00) and HDF library (v4.1r2). It has also been ported to the following platforms: solaris -- Sun4 SPARC running SunOS 5.5. irix6.2 -- SGI running IRIX version 6.2 n32-bit mode. hpux10.20 -- HP9000/755 running HP-UX 10.20. dig-unix -- DEC Alpha running Digital Unix v4.0. The software can be retrieved via anonymous ftp at the following URL: ftp://hdf.ncsa.uiuc.edu/pub/HCR/Software/HCR2.0v1.2.tar Untar the file and display the README file for installation instructions. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - For questions regarding these or other HDF issues, contact: hdfhelp@ncsa.uiuc.edu