H5Part development and discussion

[Andreas Adelmann <andreas.adelmann AT psi.ch>]

--
Dr. sc. math. Andreas (Andy) Adelmann
Staff Scientist
Paul Scherrer Institut WLGA U125 CH-5232 Villigen PSI
Phone Office: xx41 56 310 42 33 Fax: xx41 56 310 31 91
Phone Home: xx41 62 891 91 44

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• From: Andreas Adelmann <andreas.adelmann AT psi.ch>
• To: John Biddiscombe <biddisco AT cscs.ch>
• Cc: h5part AT list.psi.ch
• Subject: Re: sparticles
• Date: Wed, 26 Jul 2006 15:51:17 +0200

Andreas et al,

I've done quite a lot of work on fixing and improving my particle rendering program recently and I'm now beginning some benchmarking tests (of both disk, file formats, network as well as graphics) and am starting the ball rolling by adopting the H5Part format for the saving of my own Particle data (from other sources etc). I've found a number of "issues" that I'd like to address regarding the H5Part format, and I'm also quite short of H5Part test data (I have one large dataset from yourself with a million particles, but the timesteps seem so big that animations of the data do not seem very interesting. Also the scalar values are px,py,pz and id which do not give much to display. Do you have any other data in h5Part format that I may use to experiment with?

Hello John I am on my track toward vacation I am happy to come back on the subject after I am returning to PSI around August 7.

Also, I understand that you are in general plotting data in a phase space where x,y,z may in fact be an arbitrary scalar?

YES!

Achim could you please look at the 3 items/question and discuss this with the LBNL folks? Thanks

Two H5Part items spring to mind
1 : when reading (for example, position) arrays from file, one must read X, then Y, then Z, copy them into a final {x,y,z} array, HDF5 should allow reading with strides so that a single read can place the data into the array in the layout preferred. I will make some changes to the H5Part API to support this. On a similar note, reading subsets of data, or data where every N'th point is read should also be supported.
2 : There is no real support for other datatypes within the H5Part API, the id,px,py,pz,x,y,z are hardcoded and the datatypes are preset.
3 : The H5Part format is really not very general purpose - storing SPH data and DEM data in there is requiring me to add various methods to the API.

All the best Andreas

--
Dr. sc. math. Andreas (Andy) Adelmann
Staff Scientist
Paul Scherrer Institut WLGA U125 CH-5232 Villigen PSI
Phone Office: xx41 56 310 42 33 Fax: xx41 56 310 31 91
Phone Home: xx41 62 891 91 44


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