Data compression vrs Tiling

Ray Osborn ROsborn at
Fri Feb 25 19:56:27 GMT 2000

on 2000/02/25 1:24 PM, Paul Langan at langan_paul at wrote:

> One other thing related to my ignorance of programming. I could not use the
> 1.3.1 API untill I had edited the header file to select the appropriate
> calling
> convention for my PC (winNT C++)
> #       define MANGLE(__arg)            CONCAT(__arg,_)
> Is this because I'm not using the API correctly or just becuase I didn't read
> the installation note properly?

Freddie Akeroyd is probably the best person to answer this point.  Between v
1.2.0 and 1.3.0, the following change was made :

- Add __stdcall definition to C prototypes under WIN32 so they can link
  to FORTRAN. 

There are two other mangle options commented out in napi.h.  Perhaps we
should make it clear in the README files that the user may have to
experiment with these to get the one that works with their compiler.  I
don't know if it's possible to refine the #ifdefs to make them work more

on 2000/02/25 1:58 PM, Brian Tieman at tieman at wrote:

> As for the problem with the fortner browser, I've never gotten it to
> crash, but if there are a large number of groups, it can take a very
> long time to forever to open the file.  This has actually scared some
> people in my group away from Nexus because they think the long time it
> can take the browser to open files is a sign of how slow HDF is as a
> file system.  I've only seen these long file read times with the fortner
> browser, however.  My homebrew code reads and writes files as fast as
> can be expected.

Have you tried compiling NXbrowse.c?  Although it's not written for GUI
systems, I find it works perfectly well on my Mac when compiled with a
terminal emulation library (a standard option in Metrowerks Codewarrior).  I
assume that similar options are available on Windows NT machines.  In fact,
we should probably distribute binary executable versions for different
systems.  At least we would then be able to make independent demonstrations
of typical NeXus performance.

In fact, if anyone wanted to use NXbrowse.c as the basis for writing a GUI
browser of their own (Mac, PC, IDL?), I would encourage you to do so.  I
don't really have enough experience of this sort of programming to do it
myself, but it would be an invaluable contribution to the NeXus project.


P.S. We're about to release a new version of NXbrowse.c and napi.c,
addressing the recent int32 issue.
Dr Ray Osborn                Tel: +1 (630) 252-9011
Materials Science Division   Fax: +1 (630) 252-7777
Argonne National Laboratory  E-mail: ROsborn at
Argonne, IL 60439-4845


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