From mcgrath@ncsa.uiuc.edu Tue Sep 2 18:25:47 1997 Path: newsfeed.cv.nrao.edu!newsgate.duke.edu!nntprelay.mathworks.com!howland.erols.net!vixen.cso.uiuc.edu!not-for-mail From: Robert McGrath Newsgroups: sci.data.formats Subject: Re: HDF and Java Date: Tue, 02 Sep 1997 13:33:48 -0500 Organization: University of Illinois at Urbana-Champaign Lines: 48 Message-ID: <340C5C0C.167E@ncsa.uiuc.edu> References: <3405E750.41C6@krazy.jpl.nasa.gov> NNTP-Posting-Host: webstar.ncsa.uiuc.edu Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.01SC-SGI (X11; I; IRIX 5.3 IP22) To: William Weibel Xref: newsfeed.cv.nrao.edu sci.data.formats:92 William Weibel wrote: > > Hello, > > Our group is interested in building a Java interface to HDF. > Our dream is that this would be fully written in Java, and not > simply wrapped around the C-based native HDF code. > Is anyone else thinking along these lines? > To give a more detailed response: NCSA has now released the official wrapper. Yes, we've thought a lot about a pure Java implementation, but we didn't even try. We have not attempted to implement HDF in Java because the HDF library is extremely large (> 100K lines of C). Much of the usefulness of HDF (compression, chunking, etc.) is in the library code, not the disk format, so the Java implementation would have to mimic the semantics of the C code--a significant piece of reverse engineering. Obviously, you might want to create Java classes for your favorite subset of HDF. One may wonder how easily the files would interoperate with the "regular" library. Since HDF is, by definition, doing file I/O, a pure Java version of HDF isn't likely to work well in a Java enabled browser in any case. In general, we are pursuing an architecture in which the C library and server classes reside where ever there is HDF data, and Java applets access HDF files through remote interfaces. Thus the client side could be pure java, with the data wrapped with an impure Java/C server. We hope to have some standard classes like this available later this year. -- Robert E. McGrath (HDF Java Team Leader) National Center for Supercomputing Applications University of Illinois, Urbana-Champaign Champaign, Illinois 61820 (217)-333-6549 mcgrath@ncsa.uiuc.edu From mcgrath@ncsa.uiuc.edu Tue Sep 2 18:26:55 1997 Path: newsfeed.cv.nrao.edu!newsgate.duke.edu!nntprelay.mathworks.com!news.maxwell.syr.edu!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!ais.net!vixen.cso.uiuc.edu!not-for-mail From: Robert McGrath Newsgroups: sci.data.formats Subject: Re: HDF and Java Date: Tue, 02 Sep 1997 13:46:09 -0500 Organization: University of Illinois at Urbana-Champaign Lines: 52 Message-ID: <340C5EF1.2781@ncsa.uiuc.edu> References: <3405E750.41C6@krazy.jpl.nasa.gov> NNTP-Posting-Host: webstar.ncsa.uiuc.edu Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.01SC-SGI (X11; I; IRIX 5.3 IP22) Xref: newsfeed.cv.nrao.edu sci.data.formats:93 William Weibel wrote: > > Hello, > > Our group is interested in building a Java interface to HDF. > Our dream is that this would be fully written in Java, and not > simply wrapped around the C-based native HDF code. > Is anyone else thinking along these lines? > > Thank-you > William Weibel > Sorry if this is a repeat, I'm learning a new newsreader. NCSA has just released the "official" wrapper for the C library. http://hdf.ncsa.uiuc.edu/java-hdf-html/ Yes, we've thought a lot about a pure Java implementation. But we aren't attempting to do this at this time. * The HDF library is huge (> 100K lines of C). Many of the useful features (compression, chunking, data conversion across platforms) are in the library, not the files. So you need to mimic the C code, which is a big project. * HDF is doing I/O, so a pure Java implementation still won't work in most browsers. Our general approach is to work toward an architecture where there is a wrapped library wherever there are are HDF files to access. Clients would use applets that access HDF through remote interfaces. The clients can be pure java and downloadable applets. The data comes from impure C/Java servers. Obviously, someone could write their own classes for their favorite subset of HDF. Assuring interoperability could be tricky, though. -- Robert E. McGrath (HDF Java Team Leader) National Center for Supercomputing Applications University of Illinois, Urbana-Champaign Champaign, Illinois 61820 (217)-333-6549 mcgrath@ncsa.uiuc.edu From " dean"@cira.colostate.edu Wed Sep 10 10:14:20 1997 Path: newsfeed.cv.nrao.edu!newsgate.duke.edu!nntprelay.mathworks.com!news.mathworks.com!gatech!purdue!yuma!usenet From: Kelly Dean <" dean"@cira.colostate.edu> Newsgroups: sci.data.formats,comp.lang.idl-pvwave Subject: Re: HDF Browser for Win 95 Date: Tue, 09 Sep 1997 11:10:13 -0600 Organization: Colorado State University, Fort Collins, CO 80523 Lines: 23 Message-ID: <341582F4.80D8BB08@cira.colostate.edu> References: <34156856.4743@iap.unibe.ch> NNTP-Posting-Host: mranda.cira.colostate.edu Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 4.01 [en] (WinNT; I) X-Priority: 3 (Normal) Xref: newsfeed.cv.nrao.edu sci.data.formats:97 comp.lang.idl-pvwave:605 hiltbrunner@iap.unibe.ch wrote: > Hi folks! > > Are there any other shareware browsers for HDF files running under > Windows 95 apart those from Fortner (Browser, Plot, Transform), > Collage > and Mosaic 2.0 ?? > > Thanx for any URLS or hints... > > Regards > > Daniel NCSA recently release a HDF Veiwer - written in Java. You can find it at: http://hdf.ncsa.uiuc.edu/java-hdf-html/ Kelly From mcgrath@ncsa.uiuc.edu Wed Sep 10 16:36:30 1997 Path: newsfeed.cv.nrao.edu!newsgate.duke.edu!nntprelay.mathworks.com!howland.erols.net!vixen.cso.uiuc.edu!not-for-mail From: Robert McGrath Newsgroups: sci.data.formats,comp.lang.idl-pvwave Subject: Re: HDF Browser for Win 95 Date: Wed, 10 Sep 1997 12:48:33 -0500 Organization: University of Illinois at Urbana-Champaign Lines: 34 Message-ID: <3416DD71.41C6@ncsa.uiuc.edu> References: <34156856.4743@iap.unibe.ch> NNTP-Posting-Host: webstar.ncsa.uiuc.edu Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.01SC-SGI (X11; I; IRIX 5.3 IP22) To: hiltbrunner@iap.unibe.ch Xref: newsfeed.cv.nrao.edu sci.data.formats:99 comp.lang.idl-pvwave:607 hiltbrunner@iap.unibe.ch wrote: > > Hi folks! > > Are there any other shareware browsers for HDF files running under > Windows 95 apart those from Fortner (Browser, Plot, Transform), Collage > and Mosaic 2.0 ?? > > Thanx for any URLS or hints... > > Regards > > Daniel The NCSA Java HDF Viewer has been released, including full source code. http://hdf.ncsa.uiuc.edu/java-hdf-html/ The JHV is under active development by the NCSA HDF team, so there will be further improvements. This tool is intended to replace Collage. Since we've released the Java source, it should also be reasonably easy to customize. -- Robert E. McGrath (HDF Java Team Leader) National Center for Supercomputing Applications University of Illinois, Urbana-Champaign Champaign, Illinois 61820 (217)-333-6549 mcgrath@ncsa.uiuc.edu