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 <[email protected]>:
> 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 <[email protected]> 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”. ;-)
>>
>>
>>
>> regards, Alex.
>>
>>
>>
>>
>> Managing Directors: Dr. Seok Cheol Kee, Andrea Weuffen, Wolfgang Vieweger
>>
>> Von: Hdf-forum [mailto:[email protected]] 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.
>> [email protected]
>>
>> 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.
> [email protected]
> 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/

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

Reply via email to