How can I compare two Hd5 files?

Hdf-forum archives
1

I tried to compare two files, that looked identical,l with Beyond Compare and it found lots of small differences. Are the differences real or do they have something to do with generating them at a different time?

Thanks,

Robert Coleman
The Boeing Company
MIS-USN Software Engineer
Robert.W.Coleman2@boeing.com
314-777-6418

[cid:image001.png@01CBE864.A49198D0]

2

Hi, Robert!

  I had a similar issue and I suspect the differences are due to the object
time tracking in HDF5:

  http://www.hdfgroup.org/hdf5-quest.html#bit-for-bit

  BTW, has anyone tested HDF5 library against Y2038 problem?

···

--
HDF: Software that Powers Science

On Mon, Dec 16, 2013 at 12:13 PM, Coleman, Robert W < Robert.W.Coleman2@boeing.com> wrote:

I tried to compare two files, that looked identical,l with Beyond
Compare and it found lots of small differences. Are the differences real
or do they have something to do with generating them at a different time?

Thanks,

*Robert Coleman*
The Boeing Company
MIS-USN Software Engineer
Robert.W.Coleman2@boeing.com
314-777-6418

[image: cid:image001.png@01CBE864.A49198D0]

_______________________________________________
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

3

Hi Joe,

Thanks for the info, I suspected that but was not sure. It says that you can turn if off somehow. We have those API's packaged up in a COM library. Not sure how to turn It off. Is it in a configuration file or something?

Thanks again Joe!!

Rob

···

From: Hdf-forum [mailto:hdf-forum-bounces@lists.hdfgroup.org] On Behalf Of H. Joe Lee
Sent: Monday, December 16, 2013 1:32 PM
To: HDF Users Discussion List
Subject: Re: [Hdf-forum] How can I compare two Hd5 files?

Hi, Robert!

  I had a similar issue and I suspect the differences are due to the object time tracking in HDF5:

  http://www.hdfgroup.org/hdf5-quest.html#bit-for-bit

  BTW, has anyone tested HDF5 library against Y2038 problem?

--
HDF: Software that Powers Science

On Mon, Dec 16, 2013 at 12:13 PM, Coleman, Robert W <Robert.W.Coleman2@boeing.com<mailto:Robert.W.Coleman2@boeing.com>> wrote:
I tried to compare two files, that looked identical,l with Beyond Compare and it found lots of small differences. Are the differences real or do they have something to do with generating them at a different time?

Thanks,

Robert Coleman
The Boeing Company
MIS-USN Software Engineer
Robert.W.Coleman2@boeing.com<mailto:Robert.W.Coleman2@boeing.com>
314-777-6418<tel:314-777-6418>
[cid:image001.png@01CBE864.A49198D0]

_______________________________________________
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

4

Hi Joe,

Hi, Robert!

  I had a similar issue and I suspect the differences are due to the object time tracking in HDF5:

  http://www.hdfgroup.org/hdf5-quest.html#bit-for-bit

  BTW, has anyone tested HDF5 library against Y2038 problem?

Why bother? Someone (I doubt that it will be the same team) will need to update the code, file format, docs, etc. (as everyone else who uses time_t) and deal with compatibility issues. Let's hope that in 24 years HDF5 will still be relevant and ingenious people will come up with a solution :-).

On a more serious note, HDF5 doesn't use time for its internal operations. Time is stored as any other type of data, i.e., applications should be dealing with this issue.

Elena

···

On Dec 16, 2013, at 1:32 PM, H. Joe Lee <hyoklee@hdfgroup.org> wrote:

--
HDF: Software that Powers Science

On Mon, Dec 16, 2013 at 12:13 PM, Coleman, Robert W <Robert.W.Coleman2@boeing.com> wrote:
I tried to compare two files, that looked identical,l with Beyond Compare and it found lots of small differences. Are the differences real or do they have something to do with generating them at a different time?

Thanks,

Robert Coleman
The Boeing Company
MIS-USN Software Engineer
Robert.W.Coleman2@boeing.com
314-777-6418

<image001.jpg>

_______________________________________________
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

_______________________________________________
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

5

Rob,

It is in the PropertyList you pass to the datasets at creation time. The C
API for setting the property is here:

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

Support for this was recently implemented in h5py (
Issue 225 by tacaswell · Pull Request #271 · h5py/h5py · GitHub ) which might help as an example of
how to turn off time tracking.

Tom

···

On Mon, Dec 16, 2013 at 2:39 PM, Coleman, Robert W < Robert.W.Coleman2@boeing.com> wrote:

Hi Joe,

Thanks for the info, I suspected that but was not sure. It says that you
can turn if off somehow. We have those API’s packaged up in a COM
library. Not sure how to turn It off. Is it in a configuration file or
something?

Thanks again Joe!!

Rob

*From:* Hdf-forum [mailto:hdf-forum-bounces@lists.hdfgroup.org] *On
Behalf Of *H. Joe Lee
*Sent:* Monday, December 16, 2013 1:32 PM
*To:* HDF Users Discussion List
*Subject:* Re: [Hdf-forum] How can I compare two Hd5 files?

Hi, Robert!

  I had a similar issue and I suspect the differences are due to the
object time tracking in HDF5:

  http://www.hdfgroup.org/hdf5-quest.html#bit-for-bit

  BTW, has anyone tested HDF5 library against Y2038 problem?

--
HDF: Software that Powers Science

On Mon, Dec 16, 2013 at 12:13 PM, Coleman, Robert W < > Robert.W.Coleman2@boeing.com> wrote:

I tried to compare two files, that looked identical,l with Beyond Compare
and it found lots of small differences. Are the differences real or do
they have something to do with generating them at a different time?

Thanks,

*Robert Coleman*
The Boeing Company
MIS-USN Software Engineer
Robert.W.Coleman2@boeing.com
314-777-6418

[image: cid:image001.png@01CBE864.A49198D0]

_______________________________________________
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

_______________________________________________
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

--
Thomas A Caswell
PhD Candidate University of Chicago
Nagel and Gardel labs
tcaswell@uchicago.edu
jfi.uchicago.edu/~tcaswell
o: 773.702.7204

6

Rob,

You will need to modify the way objects are created by turning off time tracking. See the H5Pset_obj_track_times function http://www.hdfgroup.org/HDF5/doc/RM/RM_H5P.html#Property-SetObjTrackTimes.

Elena

···

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Elena Pourmal The HDF Group http://hdfgroup.org
1800 So. Oak St., Suite 203, Champaign IL 61820
217.531.6112
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

On Dec 16, 2013, at 2:39 PM, "Coleman, Robert W" <Robert.W.Coleman2@boeing.com> wrote:

Hi Joe,

Thanks for the info, I suspected that but was not sure. It says that you can turn if off somehow. We have those API’s packaged up in a COM library. Not sure how to turn It off. Is it in a configuration file or something?

Thanks again Joe!!

Rob

From: Hdf-forum [mailto:hdf-forum-bounces@lists.hdfgroup.org] On Behalf Of H. Joe Lee
Sent: Monday, December 16, 2013 1:32 PM
To: HDF Users Discussion List
Subject: Re: [Hdf-forum] How can I compare two Hd5 files?

Hi, Robert!

  I had a similar issue and I suspect the differences are due to the object time tracking in HDF5:

  http://www.hdfgroup.org/hdf5-quest.html#bit-for-bit

  BTW, has anyone tested HDF5 library against Y2038 problem?

--
HDF: Software that Powers Science

On Mon, Dec 16, 2013 at 12:13 PM, Coleman, Robert W <Robert.W.Coleman2@boeing.com> wrote:
I tried to compare two files, that looked identical,l with Beyond Compare and it found lots of small differences. Are the differences real or do they have something to do with generating them at a different time?

Thanks,

Robert Coleman
The Boeing Company
MIS-USN Software Engineer
Robert.W.Coleman2@boeing.com
314-777-6418

<image001.jpg>

_______________________________________________
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

_______________________________________________
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