Identical HDF5 files according to "h5diff" differ in comparison with "diff" Unix command

Hdf-forum archives
1

Dear all,

For the two versions of the same HDF5 file, h5diff comparison outputs "0
differences found"; however, when compared with the Unix "diff" command,
they differ. This is creating inconvenience under version control system.
Do you have any suggestions why diff and h5diff conflicts? As far as I
remember, this was not the case in the past and I remember managing HDF5
data files without problems under GIT DVCS; however, I cannot recall which
version of the HDF5 library.

I tried this as below:

I compiled my Fortran program (using GNU Fortran 4.8.2) and ran it so as to
create the HDF5 datafile as output. I moved the datafile to some other
directory. Then I re-ran my program (without recompiling) and then compared
the newly created HDF5 data file with the old one using "diff" tool in Mac
OS X (10.9.4) and Linux (Debian Wheezy 7.6 x64) and they did differ. Why?

My HDF5 version is 1.8.12 and diff version is GNU diffutils 2.8.1.

Thank you in advance,

Ekin

2

Without any deep knowledge in the subject details…

HDF5 is a container format that uses miscellaneous techniques
for the purpose of storing those data.
Some of them are e.g. binary trees, or chunking, or changing size of length values.

Even if the data is the very same and even if any reader will see the same data
there can still be many cases where the encapsulation might see differences.

A binary tree can see different layouts.
A chunking value can be tuned differently depending on platform, file system or even the used compiler.
A size of a length value might be selected differently by default.

A low level parsing of the container format will unveil what the origin is.
This is not a bug – instead that is a feature.

Maybe your invalid approach for the comparison is the real “bug”. :wink:

regards, Alex.

Managing Directors: Dr. Seok Cheol Kee, Andrea Weuffen, Wolfgang Vieweger

···

Von: Hdf-forum [mailto:hdf-forum-bounces@lists.hdfgroup.org] Im Auftrag von Ekin Akoglu
Gesendet: Dienstag, 5. August 2014 15:15
An: HDF Users Discussion List
Betreff: [Hdf-forum] Identical HDF5 files according to "h5diff" differ in comparison with "diff" Unix command

Dear all,

For the two versions of the same HDF5 file, h5diff comparison outputs "0 differences found"; however, when compared with the Unix "diff" command, they differ. This is creating inconvenience under version control system. Do you have any suggestions why diff and h5diff conflicts? As far as I remember, this was not the case in the past and I remember managing HDF5 data files without problems under GIT DVCS; however, I cannot recall which version of the HDF5 library.

I tried this as below:

I compiled my Fortran program (using GNU Fortran 4.8.2) and ran it so as to create the HDF5 datafile as output. I moved the datafile to some other directory. Then I re-ran my program (without recompiling) and then compared the newly created HDF5 data file with the old one using "diff" tool in Mac OS X (10.9.4) and Linux (Debian Wheezy 7.6 x64) and they did differ. Why?

My HDF5 version is 1.8.12 and diff version is GNU diffutils 2.8.1.

Thank you in advance,

Ekin

3

Dear Alex,

Thank you for the reply. I think I need to make something clearer. I did
not make cross-comparison of HDF5 files between the Mac OS X and Debian
Linux systems. What I wanted to mean was that I tried the example I
depicted in my previous mail on both of those Unix-like systems and the
data files did differ. To me, this could be a bug, either in difftool or in
HDF5. But I remember that in the past I did not encounter such a problem
under GIT DVCS (I think for the releases before 1.8.12). If more
information is required, I can make trials with earlier HDF5 versions (<=
1.8.11) and report the results.

Thank you,

Ekin

···

On 5 August 2014 15:26, Stohr, Alexander <Alexander.Stohr@hdle.com> wrote:

Without any deep knowledge in the subject details…

HDF5 is a container format that uses miscellaneous techniques

for the purpose of storing those data.

Some of them are e.g. binary trees, or chunking, or changing size of
length values.

Even if the data is the very same and even if any reader will see the same
data

there can still be many cases where the encapsulation might see
differences.

A binary tree can see different layouts.

A chunking value can be tuned differently depending on platform, file
system or even the used compiler.

A size of a length value might be selected differently by default.

A low level parsing of the container format will unveil what the origin is.

This is not a bug – instead that is a feature.

Maybe your invalid approach for the comparison is the real “bug”. :wink:

regards, Alex.

Managing Directors: Dr. Seok Cheol Kee, Andrea Weuffen, Wolfgang Vieweger

*Von:* Hdf-forum [mailto:hdf-forum-bounces@lists.hdfgroup.org] *Im
Auftrag von *Ekin Akoglu
*Gesendet:* Dienstag, 5. August 2014 15:15
*An:* HDF Users Discussion List
*Betreff:* [Hdf-forum] Identical HDF5 files according to "h5diff" differ
in comparison with "diff" Unix command

Dear all,

For the two versions of the same HDF5 file, h5diff comparison outputs "0
differences found"; however, when compared with the Unix "diff" command,
they differ. This is creating inconvenience under version control system.
Do you have any suggestions why diff and h5diff conflicts? As far as I
remember, this was not the case in the past and I remember managing HDF5
data files without problems under GIT DVCS; however, I cannot recall which
version of the HDF5 library.

I tried this as below:

I compiled my Fortran program (using GNU Fortran 4.8.2) and ran it so as
to create the HDF5 datafile as output. I moved the datafile to some other
directory. Then I re-ran my program (without recompiling) and then compared
the newly created HDF5 data file with the old one using "diff" tool in Mac
OS X (10.9.4) and Linux (Debian Wheezy 7.6 x64) and they did differ. Why?

My HDF5 version is 1.8.12 and diff version is GNU diffutils 2.8.1.

Thank you in advance,

Ekin

_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@lists.hdfgroup.org

http://mail.lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org
Twitter: https://twitter.com/hdf5

4

HDF5, when using the newest version's library features, includes time stamps in the file, as "h5ls -v" displays:

  h5ls -v LOD.f5
Opened "LOD.f5" with sec2 driver.
Charts Group
     Location: 1:70486
     Links: 1
     Modified: 2014-07-15 15:57:53 W. Europe Daylight Time
TableOfContents Group
     Attribute: version {3}
         Type: native int
     Location: 1:342
     Links: 1
     Modified: 2014-07-15 15:57:53 W. Europe Daylight Time
     Comment: "All file objects in reverse order for easier browsing. "
t=000000000.0000000000 Group
     Attribute: Time scalar
         Type: native double
     Location: 1:195
     Links: 1
     Modified: 2014-07-15 15:57:53 W. Europe Daylight Time

However, you can control whether the newest library features are used or not by calling

  H5Pset_libver_bounds(fapl_id, H5F_LIBVER_EARLIEST, H5F_LIBVER_LATEST);

see

http://www.hdfgroup.org/HDF5/doc/RM/RM_H5P.html#Property-SetLibverBounds

Thereby you should be able to disable timestamps to be put into the HDF5 file by forcing it to *not* use the newest library features and binary diffs should work again for such old-style files.

Cheers,
           Werner

···

Data: 0, 1, 5
         Data: 0

On 05.08.2014 15:14, Ekin Akoglu wrote:

Dear all,

For the two versions of the same HDF5 file, h5diff comparison outputs "0 differences found"; however, when compared with the Unix "diff" command, they differ. This is creating inconvenience under version control system. Do you have any suggestions why diff and h5diff conflicts? As far as I remember, this was not the case in the past and I remember managing HDF5 data files without problems under GIT DVCS; however, I cannot recall which version of the HDF5 library.

I tried this as below:

I compiled my Fortran program (using GNU Fortran 4.8.2) and ran it so as to create the HDF5 datafile as output. I moved the datafile to some other directory. Then I re-ran my program (without recompiling) and then compared the newly created HDF5 data file with the old one using "diff" tool in Mac OS X (10.9.4) and Linux (Debian Wheezy 7.6 x64) and they did differ. Why?

My HDF5 version is 1.8.12 and diff version is GNU diffutils 2.8.1.

Thank you in advance,

Ekin

_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@lists.hdfgroup.org
http://mail.lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org
Twitter: https://twitter.com/hdf5

--
___________________________________________________________________________
Dr. Werner Benger Visualization Research
Center for Computation & Technology at Louisiana State University (CCT/LSU)
2019 Digital Media Center, Baton Rouge, Louisiana 70803
Tel.: +1 225 578 4809 Fax.: +1 225 578-5362

5

Hi,

I think I also witnessed the difference. If you do a h5dump, you may
see that some values are different. If you create twice the same file
with the same procedure, it may also be different. I guess there is a
timestamp or something like that in the file.

Cheers,

Matthieu

···

2014-08-05 15:43 GMT+02:00 Ekin Akoglu <ekin@ims.metu.edu.tr>:

Dear Alex,

Thank you for the reply. I think I need to make something clearer. I did not
make cross-comparison of HDF5 files between the Mac OS X and Debian Linux
systems. What I wanted to mean was that I tried the example I depicted in my
previous mail on both of those Unix-like systems and the data files did
differ. To me, this could be a bug, either in difftool or in HDF5. But I
remember that in the past I did not encounter such a problem under GIT DVCS
(I think for the releases before 1.8.12). If more information is required, I
can make trials with earlier HDF5 versions (<= 1.8.11) and report the
results.

Thank you,

Ekin

On 5 August 2014 15:26, Stohr, Alexander <Alexander.Stohr@hdle.com> wrote:

Without any deep knowledge in the subject details…

HDF5 is a container format that uses miscellaneous techniques

for the purpose of storing those data.

Some of them are e.g. binary trees, or chunking, or changing size of
length values.

Even if the data is the very same and even if any reader will see the same
data

there can still be many cases where the encapsulation might see
differences.

A binary tree can see different layouts.

A chunking value can be tuned differently depending on platform, file
system or even the used compiler.

A size of a length value might be selected differently by default.

A low level parsing of the container format will unveil what the origin
is.

This is not a bug – instead that is a feature.

Maybe your invalid approach for the comparison is the real “bug”. :wink:

regards, Alex.

Managing Directors: Dr. Seok Cheol Kee, Andrea Weuffen, Wolfgang Vieweger

Von: Hdf-forum [mailto:hdf-forum-bounces@lists.hdfgroup.org] Im Auftrag
von Ekin Akoglu
Gesendet: Dienstag, 5. August 2014 15:15
An: HDF Users Discussion List
Betreff: [Hdf-forum] Identical HDF5 files according to "h5diff" differ in
comparison with "diff" Unix command

Dear all,

For the two versions of the same HDF5 file, h5diff comparison outputs "0
differences found"; however, when compared with the Unix "diff" command,
they differ. This is creating inconvenience under version control system. Do
you have any suggestions why diff and h5diff conflicts? As far as I
remember, this was not the case in the past and I remember managing HDF5
data files without problems under GIT DVCS; however, I cannot recall which
version of the HDF5 library.

I tried this as below:

I compiled my Fortran program (using GNU Fortran 4.8.2) and ran it so as
to create the HDF5 datafile as output. I moved the datafile to some other
directory. Then I re-ran my program (without recompiling) and then compared
the newly created HDF5 data file with the old one using "diff" tool in Mac
OS X (10.9.4) and Linux (Debian Wheezy 7.6 x64) and they did differ. Why?

My HDF5 version is 1.8.12 and diff version is GNU diffutils 2.8.1.

Thank you in advance,

Ekin

_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@lists.hdfgroup.org

http://mail.lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org
Twitter: https://twitter.com/hdf5

_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@lists.hdfgroup.org
http://mail.lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org
Twitter: https://twitter.com/hdf5

--
Information System Engineer, Ph.D.
Blog: http://matt.eifelle.com
LinkedIn: http://www.linkedin.com/in/matthieubrucher
Music band: http://liliejay.com/

6

Dear Alex,

Thank you for the reply. I think I need to make something clearer. I did
not make cross-comparison of HDF5 files between the Mac OS X and Debian
Linux systems. What I wanted to mean was that I tried the example I
depicted in my previous mail on both of those Unix-like systems and the
data files did differ. To me, this could be a bug, either in difftool or in
HDF5. But I remember that in the past I did not encounter such a problem
under GIT DVCS (I think for the releases before 1.8.12). If more
information is required, I can make trials with earlier HDF5 versions (<=
1.8.11) and report the results.

Dear Ekin,

As a HDF5 user, I would not expect HDF5 files with the same data to match with a
tool like diff (or the diff tool of git or any other vcs). HDF5 uses more
advanced techniques with respect to plain ASCII files, which is why we use it.
As a consequence you should not expect any kind of binary equality between
files, even between files created similarly.

Also, in recent versions of HDF5 there is data creation and modification time
tracking. That would certainly cause a difference.

It may have worked at some point for you but as it is not a design goal of HDF5.
The topic of hdf5 vcs data has been discussed at these places, for instance:


If you still want to manage your data with git, which is fine, you may want to
use git-annex that handles binary data (although text-based diffing is not
used): https://git-annex.branchable.com/

Regards,

Pierre

···

On Tue, Aug 05, 2014 at 03:43:12PM +0200, Ekin Akoglu wrote:

Thank you,

Ekin

On 5 August 2014 15:26, Stohr, Alexander <Alexander.Stohr@hdle.com> wrote:

> Without any deep knowledge in the subject details…
>
>
>
> HDF5 is a container format that uses miscellaneous techniques
>
> for the purpose of storing those data.
>
> Some of them are e.g. binary trees, or chunking, or changing size of
> length values.
>
>
>
> Even if the data is the very same and even if any reader will see the same
> data
>
> there can still be many cases where the encapsulation might see
> differences.
>
>
>
> A binary tree can see different layouts.
>
> A chunking value can be tuned differently depending on platform, file
> system or even the used compiler.
>
> A size of a length value might be selected differently by default.
>
>
>
> A low level parsing of the container format will unveil what the origin is.
>
> This is not a bug – instead that is a feature.
>
>
>
> Maybe your invalid approach for the comparison is the real “bug”. :wink:
>
>
>
> regards, Alex.
>
>
>
>
> Managing Directors: Dr. Seok Cheol Kee, Andrea Weuffen, Wolfgang Vieweger
>
> *Von:* Hdf-forum [mailto:hdf-forum-bounces@lists.hdfgroup.org] *Im
> Auftrag von *Ekin Akoglu
> *Gesendet:* Dienstag, 5. August 2014 15:15
> *An:* HDF Users Discussion List
> *Betreff:* [Hdf-forum] Identical HDF5 files according to "h5diff" differ
> in comparison with "diff" Unix command
>
>
>
> Dear all,
>
>
>
> For the two versions of the same HDF5 file, h5diff comparison outputs "0
> differences found"; however, when compared with the Unix "diff" command,
> they differ. This is creating inconvenience under version control system.
> Do you have any suggestions why diff and h5diff conflicts? As far as I
> remember, this was not the case in the past and I remember managing HDF5
> data files without problems under GIT DVCS; however, I cannot recall which
> version of the HDF5 library.
>
>
>
> I tried this as below:
>
>
>
> I compiled my Fortran program (using GNU Fortran 4.8.2) and ran it so as
> to create the HDF5 datafile as output. I moved the datafile to some other
> directory. Then I re-ran my program (without recompiling) and then compared
> the newly created HDF5 data file with the old one using "diff" tool in Mac
> OS X (10.9.4) and Linux (Debian Wheezy 7.6 x64) and they did differ. Why?
>
>
>
> My HDF5 version is 1.8.12 and diff version is GNU diffutils 2.8.1.
>

7

Thank you all for the suggestions and brainstorming thus far.

Like Rob, I would also expect that HDF5 binaries be equal. But suggestion
by Werner is also a workaround for me for now.

In the meantime, I went from HDF5 release 1.8.12 down to as far back as
HDF5 1.8.8 with Intel Fortran Compiler 14.0.3 on an Ubuntu 12.04.4 x64
using the h5ex_t_cmpd_F03.f90
<http://www.hdfgroup.org/ftp/HDF5/examples/examples-by-api/hdf5-examples/1_8/FORTRAN/H5T/h5ex_t_cmpd_F03.f90>
example
and making trials; however, I could not manage to get binary equality out
of "diff" command for HDF5 data files created by two identical runs. This
shows that my memory of remembering managing h5 files under GIT is false,
although I was almost sure that I could do manage a GIT repo with h5 files
in the past.

Anyway, thank you all for the fruitful discussion. It seems that the
suggestion of Werner is the way to go.

Regards,

Ekin

···

On 5 August 2014 17:32, Werner Benger <werner@cct.lsu.edu> wrote:

HDF5, when using the newest version's library features, includes time
stamps in the file, as "h5ls -v" displays:

h5ls -v LOD.f5
Opened "LOD.f5" with sec2 driver.
Charts Group
    Location: 1:70486
    Links: 1
    Modified: 2014-07-15 15:57:53 W. Europe Daylight Time
TableOfContents Group
    Attribute: version {3}
        Type: native int
        Data: 0, 1, 5
    Location: 1:342
    Links: 1
    Modified: 2014-07-15 15:57:53 W. Europe Daylight Time
    Comment: "All file objects in reverse order for easier browsing. "
t=000000000.0000000000 Group
    Attribute: Time scalar
        Type: native double
        Data: 0
    Location: 1:195
    Links: 1
    Modified: 2014-07-15 15:57:53 W. Europe Daylight Time

However, you can control whether the newest library features are used or
not by calling

H5Pset_libver_bounds(fapl_id, H5F_LIBVER_EARLIEST, H5F_LIBVER_LATEST);

see

http://www.hdfgroup.org/HDF5/doc/RM/RM_H5P.html#Property-SetLibverBounds

Thereby you should be able to disable timestamps to be put into the HDF5
file by forcing it to *not* use the newest library features and binary
diffs should work again for such old-style files.

Cheers,
          Werner

On 05.08.2014 15:14, Ekin Akoglu wrote:

Dear all,

For the two versions of the same HDF5 file, h5diff comparison outputs "0
differences found"; however, when compared with the Unix "diff" command,
they differ. This is creating inconvenience under version control system.
Do you have any suggestions why diff and h5diff conflicts? As far as I
remember, this was not the case in the past and I remember managing HDF5
data files without problems under GIT DVCS; however, I cannot recall which
version of the HDF5 library.

I tried this as below:

I compiled my Fortran program (using GNU Fortran 4.8.2) and ran it so as
to create the HDF5 datafile as output. I moved the datafile to some other
directory. Then I re-ran my program (without recompiling) and then compared
the newly created HDF5 data file with the old one using "diff" tool in Mac
OS X (10.9.4) and Linux (Debian Wheezy 7.6 x64) and they did differ. Why?

My HDF5 version is 1.8.12 and diff version is GNU diffutils 2.8.1.

Thank you in advance,

Ekin

_______________________________________________
Hdf-forum is for HDF software users discussion.Hdf-forum@lists.hdfgroup.orghttp://mail.lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org
Twitter: https://twitter.com/hdf5

--
___________________________________________________________________________
Dr. Werner Benger Visualization Research
Center for Computation & Technology at Louisiana State University (CCT/LSU)
2019 Digital Media Center, Baton Rouge, Louisiana 70803
Tel.: +1 225 578 4809 Fax.: +1 225 578-5362

_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@lists.hdfgroup.org

http://mail.lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org
Twitter: https://twitter.com/hdf5

8

it may not be common for HDF5 users to request or expect "bit for bit" equivalence. It *was* a pretty important way to verify correctness in climate codes using NetCDF (I suppose bit-for-bit equivalence is now impossible with HDF5-backed netcdf files?).

==rob

···

On 08/05/2014 09:01 AM, pierre.debuyl@chem.kuleuven.be wrote:

As a HDF5 user, I would not expect HDF5 files with the same data to match with a
tool like diff (or the diff tool of git or any other vcs). HDF5 uses more
advanced techniques with respect to plain ASCII files, which is why we use it.
As a consequence you should not expect any kind of binary equality between
files, even between files created similarly.

--
Rob Latham
Mathematics and Computer Science Division
Argonne National Lab, IL USA

9

Sorry for this follow up… I feel like I forgot about one more item that might or might not hit here.

There are file formats that have members that are not valid under certain other settings.
Still those members occupy some space and thus have some value – it might be a random value.

Just if someone really wants to track down the root cause then it might or might not be the case that it is raised by such a member.

Regards, Alex.

···

Von: Hdf-forum [mailto:hdf-forum-bounces@lists.hdfgroup.org] Im Auftrag von Ekin Akoglu
Gesendet: Dienstag, 5. August 2014 17:59
An: HDF Users Discussion List
Betreff: Re: [Hdf-forum] Identical HDF5 files according to "h5diff" differ in comparison with "diff" Unix command

Thank you all for the suggestions and brainstorming thus far.

Like Rob, I would also expect that HDF5 binaries be equal. But suggestion by Werner is also a workaround for me for now.

In the meantime, I went from HDF5 release 1.8.12 down to as far back as HDF5 1.8.8 with Intel Fortran Compiler 14.0.3 on an Ubuntu 12.04.4 x64 using the h5ex_t_cmpd_F03.f90<http://www.hdfgroup.org/ftp/HDF5/examples/examples-by-api/hdf5-examples/1_8/FORTRAN/H5T/h5ex_t_cmpd_F03.f90> example and making trials; however, I could not manage to get binary equality out of "diff" command for HDF5 data files created by two identical runs. This shows that my memory of remembering managing h5 files under GIT is false, although I was almost sure that I could do manage a GIT repo with h5 files in the past.

Anyway, thank you all for the fruitful discussion. It seems that the suggestion of Werner is the way to go.

Regards,

Ekin

On 5 August 2014 17:32, Werner Benger <werner@cct.lsu.edu<mailto:werner@cct.lsu.edu>> wrote:
HDF5, when using the newest version's library features, includes time stamps in the file, as "h5ls -v" displays:

h5ls -v LOD.f5
Opened "LOD.f5" with sec2 driver.
Charts Group
    Location: 1:70486
    Links: 1
    Modified: 2014-07-15 15:57:53 W. Europe Daylight Time
TableOfContents Group
    Attribute: version {3}
        Type: native int
        Data: 0, 1, 5
    Location: 1:342
    Links: 1
    Modified: 2014-07-15 15:57:53 W. Europe Daylight Time
    Comment: "All file objects in reverse order for easier browsing. "
t=000000000.0000000000 Group
    Attribute: Time scalar
        Type: native double
        Data: 0
    Location: 1:195
    Links: 1
    Modified: 2014-07-15 15:57:53 W. Europe Daylight Time

However, you can control whether the newest library features are used or not by calling

H5Pset_libver_bounds(fapl_id, H5F_LIBVER_EARLIEST, H5F_LIBVER_LATEST);

see

http://www.hdfgroup.org/HDF5/doc/RM/RM_H5P.html#Property-SetLibverBounds

Thereby you should be able to disable timestamps to be put into the HDF5 file by forcing it to *not* use the newest library features and binary diffs should work again for such old-style files.

Cheers,
          Werner

On 05.08.2014 15:14, Ekin Akoglu wrote:
Dear all,

For the two versions of the same HDF5 file, h5diff comparison outputs "0 differences found"; however, when compared with the Unix "diff" command, they differ. This is creating inconvenience under version control system. Do you have any suggestions why diff and h5diff conflicts? As far as I remember, this was not the case in the past and I remember managing HDF5 data files without problems under GIT DVCS; however, I cannot recall which version of the HDF5 library.

I tried this as below:

I compiled my Fortran program (using GNU Fortran 4.8.2) and ran it so as to create the HDF5 datafile as output. I moved the datafile to some other directory. Then I re-ran my program (without recompiling) and then compared the newly created HDF5 data file with the old one using "diff" tool in Mac OS X (10.9.4) and Linux (Debian Wheezy 7.6 x64) and they did differ. Why?

My HDF5 version is 1.8.12 and diff version is GNU diffutils 2.8.1.

Thank you in advance,

Ekin

_______________________________________________

Hdf-forum is for HDF software users discussion.

Hdf-forum@lists.hdfgroup.org<mailto:Hdf-forum@lists.hdfgroup.org>

http://mail.lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org

Twitter: https://twitter.com/hdf5

--

___________________________________________________________________________

Dr. Werner Benger Visualization Research

Center for Computation & Technology at Louisiana State University (CCT/LSU)

2019 Digital Media Center, Baton Rouge, Louisiana 70803

Tel.: +1 225 578 4809<tel:%2B1%20225%20578%204809> Fax.: +1 225 578-5362<tel:%2B1%20225%20578-5362>

_______________________________________________
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