And to add to the problem: boxSize_Z is only declared for periodic
simulations. Using hinv3 and hinv4 as listed below the code does not
compile with TWODIMS set but PERIODIC not set.
Sander Valcke wrote:
>
> Dear gadget list,
>
> I have a small question about 2D hydro simulations in GadgetII. In
> hydra.c and density.c the following lines are used to get the inverse
> of the 2nd or 3rd power (2D) of the smoothing length:
>
> hinv3 = hinv * hinv / boxSize_Z;
> hinv4 = hinv * hinv * hinv / boxSize_Z;
>
> I do not understand why the boxSize_Z is there, why would the Z
> boxsize have any influence at all in a 2D simulation? I ran some tests
> and when commenting out the boxSize_Z the simulation results do
> differ, although the initial differences are quite small and the
> long-term qualitative evolution seems to remain the same.
>
> So, I would like to understand why that term is there, and whether I
> can safely remove it (the 2D particle densities written in the
> snapshots are the real 2D densities divided by boxSize_Z, which is a
> bit confusing).
>
> Cheerz,
>
> Sander
>
--
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| Sander Valcke |
| Sterrenkundig Observatorium, Universiteit Gent |
| Krijgslaan 281 S9, B-9000 Gent, Belgium |
| phone +32-9-264-4796 | fax +32-9-264-4989 |
| https://sourceforge.net/projects/hyplot/ |
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Sometimes the best medicine is to stop taking something.
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Received on 2009-09-29 10:12:06