Nov. 17, 1995
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HDF4.0b2 is now available on the NCSA ftp server, ftp.ncsa.uiuc.edu, in /HDF/HDF4.0.beta/.
See ABOUT_4.0b2 in HDF4.0b2/release_notes/ for more details about each item listed above.
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
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:
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.
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 is a utility that performs a quick check of two similar HDF files. Gary Fu, gfu@shark.gsfc.nasa.gov, contributed HDIFF. HDIFF is in /HDF/contrib/hdiff/ on the NCSA ftp server. (ftp.ncsa.uiuc.edu)
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.
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 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 has been released, and 2.7b3 will be released soon. Many new features have been added in 2.7b2, including:
Mosaic -xrm "Mosaic*hdfLongName: True" &
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.
There is also a newsgroup sci.data.format which was set up as a forum for discussion of HDF-related questions as well as other file formats. You may want to submit your questions there if you want to reach a larger audience.
Questions sent to hdfhelp@ncsa.uiuc.edu go directly to the HDF group.