Subject: HDF Newsletter #18

From: [email-masked] (Shiming Xu)
Date: 18 Nov 1995 02:02:31 GMT

HDF Newsletter 18
                  Nov. 17, 1995

Contents

   . HDF4.0b2 release
   . HDF<-->FITS converter
   . BIGHDF
   . Contributions 
   . Collage1.3.1 
   . Mosaic 2.7b2
   . New HDFers 

HDF4.0b2 release
----------------
    HDF4.0b2 is now available on the NCSA ftp server, ftp.ncsa.uiuc.edu, in
       /HDF/HDF4.0.beta/.

    Important changes:
      The mfhdf side library has been renamed to libmfhdf.a
      Gzip compression has been added, including the gzip library libz.a
      To link with HDF4.0b2 libraries, you need to include
        libmfhdf.a, libdf.a, libjpeg.a and libz.a. The order
        is important. 
      A new version of dimension record has been implemented, making it
        possible to store an SDS without requiring dimension scales. 
      SGI Power Challenge running IRIX6.1 is fully supported. 
      Bug fixes. 

    New features:
      GR interface supports different methods of interlacing images 
        in memory.
      Gzip library support 
      Unified configuration of library
      I/O performance improvements
      Space savings, especiall for 1-D arrays by not requiring 
        dimension scales
      Pablo performance measurement software has been integrated into 
        the HDF library, making it possible to capture performance 
        information.

    New functions added:
      Fortran functions hxscdir and hxsdir for external file access.
      SDsetdimval_comp to set compatibility mode for a dimension
      SDisdimval_bwcomp to get compatibility mode for a dimension

    See ABOUT_4.0b2 in HDF4.0b2/release_notes/ for more details about 
    each item listed above.

HDF<-->FITS converter 
--------------------
    The NCSA HDF group is working with Don Jennings,  Bill Pence
    and others on mapping between HDF and FITS. Our ultimate goal
    is to be able to convert all HDF objects to FITS and vice
    versa, making it possible to acess FITS files with HDF
    software and vice versa. This work has two parts: HDF to
    FITS(HDF2FITS) mapping and FITS to HDF(FITS2HDF) mapping. 
    For more infomation see the "HDF and FITS Conversion Information 
    Page", URL:

	http://hdf.ncsa.uiuc.edu:8001/fits

BigHDF: A next-generation HDF?
------------------------------
    HDF is showing its age.  A lot of applications seriously 
    push the limits of HDF's capabilities, in terms of the sizes 
    of objects and files that then need to create and access,
    the number of objects that can be stored in an HDF file, 
    the appropriateness and generality of the HDF object types, in 
    performance, and in other ways.  For some time, the HDF group 
    has been thinking about what it would take to completely overhaul
    HDF, to see if we can come up with a new HDF that is reasonably 
    compatible with the current HDF and at the same time addesses 
    the requirements of the 90's and beyond.

    With the help of some NASA funding, we have come up with a proposal 
    for a prototype for a next generation HDF, which we have codenamed 
    "BigHDF." BigHDF would be completely new in every respect, but it 
    would be implemented in such a way as to maintain compability with 
    older versions of HDF.

    We would now like to go public with our ideas, both to let you know 
    what we are up to and to solicit your comments and suggestions. If 
    all goes according to plan, we will create a prototype of BigHDF 
    in 1996.

    With BigHDF, we try to address the following needs that the 
    current HDF doesn't address or doesn't address well:

      * A need to store very large objects (>2 GB)
      * A need to store large numbers of objects (>20K)
      * A need for more general, flexible data models
      * Performance improvements
      * Compatibility with OODBs and distributed object technologies

    Here are some features of BigHDF, as currently proposed:

      It will support a new data model, with a single, unified object 
      type from which the current objects (raster, SDS, Vdata, etc) can
      be  derived.  The single object type will be a multidimensional 
      array of a given data type.  Data types will include the usual 
      scalar types, some new scalar types (date, time, complex, pointers), 
      and a composite (record structure) type.  Each object will have 
      a user-defined attribute list, and special storage options, 
      including the current compressed, linked-block and external
      storage options, plus some new ones such as chunked storage, 
      and possibly indexed storage.

      The file format will also be different.  Instead of creating 
      objects out of many little pieces, each with its own tag/ref, 
      BigHDF will have only one type of object, as described above, 
      and most of the information used to describe the object will 
      be contained in a header record.  Instead of identifying objects 
      with tag/ref pairs, an object identifier will be used to identify 
      objects.

    We are just finishing a draft specification for BigHDF, which we 
    will publish on the HDF Web page soon.  Have a look at it and 
    let us know what you think.

Contributions
-------------
   AipsView -- AipsView is a tool for visual data analysis built at 
             NCSA with support from the NSF/ARPA Grand Challenge 
             project in Radio Astronomy Imaging, and in cooperation 
             with the AIPS++ programming project.
             AipsView takes FITS image files (including blanked pixels)
             as input. It can also read single-SDS files written in 
            the HDF format.

            For more information please see the AipsView information 
            page at:

	         http://monet.ncsa.uiuc.edu/AipsView
    
   HDIFF -- HDIFF is a utility that performs a quick check of two similar 
            HDF files.  Gary Fu, [email-masked], contributed 
            HDIFF.  HDIFF is in /HDF/contrib/hdiff/ on the NCSA ftp 
            server. (ftp.ncsa.uiuc.edu)

   LinkWinds version 2.1 -- The Linked Windows Interactive Data System 
            (LinkWinds) is contributed by the LinkWinds Development Task 
            at NASA/JPL. LInkwinds is "a visual data exploration system 
            which has served as a testbed and prototyping environment 
            for a NASA/JPL program of research into graphical methods 
            for rapidly and interactively accessing, displaying and 
            analyzing large multivariate multidisciplinary datasets."
            LinkWinds 2.1 is in /HDF/contrib/LinkWinds/ on the NCSA
            ftp server.

   NCSA Reformat -- after adding conversions from HDF to TIFF, GIF, 
            X window dumps, Sun and raw raster, Xinjian Lu recently
            added HDF to FITS conversion capability to REFORMAT. 
            The new version is in  /HDF/contrib/NCSA/reformat on the
            NCSA ftp server. 

Collage1.3.1b1 
--------------
   Collage1.3.1b1 is now available on the NCSA ftp server, ftp.ncsa.uiuc.edu,
   in subdirectory /Visualization/Collage/Unix/Collage1.3.1b1/. New features
   of the Collage1.3.1b1 were listed in HDF Newsletter17.txt, which is 
   in /HDF/newsletters/ on the NCSA ftp server. Here we only repeat the new 
   features of the HDF browser. 
   
   The HDF browser in Collage1.3.1b1 allows users to look at different
   attributes of an HDF data set by selecting them with toggle buttons using
   the mouse. There is a new toggle frame containing the most frequently used
   6 attributes: name, long_name, valid_max, valid_min, format, unit, and the
   tag and reference number of the data set. There are also a "Default" toggle
   button that displays both tag and ref when pressed, and an  "All" toggle
   button that displays all the attributes listed above when pressed.
   The layout of the browser needs more work, and the tag values are not
   displayed correctly. These problems will be fixed in future release. 

Mosaic 2.7b2 
------------
   Mosaic 2.7b2 has been released, and 2.7b3 will be released soon.
   Many new features have been added in 2.7b2, including:
     . HDF long_name can be displayed along with the SDS (variable) name.
       This display can be turned on by using the resource Mosaic*hdfLongName.
      
	Mosaic -xrm "Mosaic*hdfLongName: True" &
 
     . All save dialogs now have a default filename
     . New features in ftp 
     . MD5 Authentication
     . Kerberos 4 & 5 Authentication 
     . Security Icon
     . Postscript Printing routines have changed
     . PNG Graphics Format is support as an in-line image format
     . E-Mail and News Signatures
     . other new features

New HDFers 
----------

Xinjian Lu, a visitor from Beijing, People's Republic of China 
  joined HDF group last August. He is now working on FITS to HDF
  converters and a FITS web browser. He also added conversion 
  functions into NCSA Reformat to convert files from HDF format 
  to other formats. 

ReuyHsia Li, a Ph. D. candidate of Computer Science, joined HDF
  group last September. She is now working on distributed HDF,
  and currently is implementing a prototype HDF that runs on
  a network of workstations.

Vivian Gray McElroy is the youngest new member of HDF. Vivian is
  the first child of Diana McElroy and Jeffery Gray. Vivian was
  born at 1:37 pm on September 11th. She is two months and seven
  days old now.