[parsec-users] extending input set for fluidanimate

Kirak Hong hokira at gatech.edu
Thu Mar 25 20:24:58 EDT 2010


Hi,

I wanted to have more input data to see different behaviors of fluidanimate
regarding different inputs.
So the possible solutions based on my understanding are :

1. clone particles (hack the input)
2. randomly generate particles
3. take inputs from outputs

Is this true?

If it is true, my problem now is that I don't know the input file format for
fluidanimate. Could you tell me what's the input format and what program
takes uses the ".fluid" files? I saw that it is from Intel RMS application,
but I have no idea about that.

Thanks!
Kirak

2010/3/25 Jim Dempsey <jim at quickthreadprogramming.com>

>  Chris, Kirak,
>
> For benchmarking I think the 500K is more than adequate for 1P or 2P
> systems. 500K x 104 = ~50MB data. On 4P or 8P systems 500K particles could
> fit in cache (at 12/24MB per processor). A larger data set would be
> appropriate for these systems. I could see a need to generate 1M, 2M, 4M, 8M
> and 16M particles. So I think a feature should be incorporated into
> fluidanimate (or application added) whereby the domain dimensions, cell size
> and and number of particles be specified, and then which will generate a
> test data set.
>
> An alternate way to accomplish this auto-magically, would be for the
> initial particle domain dimensions, cell size and particle count, be
> duplicated/multiplied as an input option. The additional particle domains
> would then be abutted together. Example,
>
> The 55 cell x 76 cell x 55 cell domain can be (by option) specified to be
> doubled, thus producing
> 110 cell by 76 cell x 55 cell particle domain, or quadrupled, thus
> producing
> 110 cell by 76 cell x 110 cell particle domain.
>
> The 76 cell Y is along the direction of gravity and would likely not need
> to be extended.
> The trailing options could be x, y, and z multipliers
>
> serial 1 0 in_500k.fluid in_2M.fluid 2 1 2
>
> Run Serial.exe, 1 thread, 0 frames, input file in_500k.fluid, output file
> in_2M.fluid, dimension x doubled, dimension y unchanged, dimension z
> doubled.
>
> Or the user could simply run with the multipliers and smaller input file
>
> This has as an additional benefit of being able to ship PARSEC with smaller
> data files.
>
> Jim
>
>
>  ------------------------------
> *From:* parsec-users-bounces at lists.cs.princeton.edu [mailto:
> parsec-users-bounces at lists.cs.princeton.edu] *On Behalf Of *Christian
> Bienia
> *Sent:* Thursday, March 25, 2010 3:40 PM
>
> *To:* 'PARSEC Users'
> *Subject:* Re: [parsec-users] extending input set for fluidanimate
>
>  Kirak,
>
>
>
> Jim’s suggestion should give you a good input with not too much work.
> Another approach would be to write a synthetic input generator that will
> generate random inputs with any amount of particles. You need to vary the
> initial position and velocity of the particles. You also must make sure that
> particles start within the bounding box and do not initially move too fast,
> otherwise the simulation will become numerically unstable. The upper bound
> on the velocity is given by the grid size and the time step size.
>
>
>
> If you use significantly more particles you might want to consider to
> increase the volume of the bounding box. The particles should fit in
> comfortably.
>
>
>
> Why exactly do you want bigger inputs?
>
>
>
> - Chris
>
>
>
>
>
> *From:* parsec-users-bounces at lists.cs.princeton.edu [mailto:
> parsec-users-bounces at lists.cs.princeton.edu] *On Behalf Of *Jim Dempsey
> *Sent:* Thursday, March 25, 2010 3:48 PM
> *To:* 'PARSEC Users'
> *Subject:* Re: [parsec-users] extending input set for fluidanimate
>
>
>
> Kirak,
>
>
>
> More than 500K particles?
>
>
>
> If so, as a quick and dirty "hack", edit the SaveFile such that it doubles
> the particle count and writes each particle twice. Run the in_500K.fluid in,
> and write out in_1M.fluid. Repeat this to double the particle counts.
> Probably it would be best to add an additional argument to specify the
> multiplier (and so you do not have to remember to remove the"hack"). You
> might want to add a randomizer to the point duplicator such that no two
> particles come in at exactly the same position. You might want to keep the
> replicated particles within a reasonably close position. Should the
> resultant file cause an explosion in the particles (blast out of the bottom
> of the domain well) you can use the display mode and let the simulation run
> until it has quieted down somewhat (but not all the way). Then reset the
> simulation without display to run to that frame number. The output file is
> now a reasonable approximation of what you might want.
>
>
>
> Jim Dempsey.
>
>
>  ------------------------------
>
> *From:* parsec-users-bounces at lists.cs.princeton.edu [mailto:
> parsec-users-bounces at lists.cs.princeton.edu] *On Behalf Of *Kirak Hong
> *Sent:* Thursday, March 25, 2010 2:35 PM
> *To:* parsec-users at lists.cs.princeton.edu
> *Subject:* [parsec-users] extending input set for fluidanimate
>
> Hi,
>
> I am trying to make more input data set for fluidanimate in parsec 2.1.
> I tried to find out input format and how to generate extra input data, but
> didn't find anything yet.
> Has anybody tried this before? Any help would be highly appreciated!
>
> Thanks!
> Kirak
>
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> parsec-users at lists.cs.princeton.edu
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>
>
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