Re: Oct-tree construction and particle insertion

From: Yves Revaz <yves.revaz_at_epfl.ch>
Date: Mon, 06 Sep 2010 09:38:33 +0200

Aldo Alberto Batta Marquez wrote:
> Dear all,
>
> I'm working on simulations of gas accretion onto a BH. Basically I
> want to modify the gravitational potential for the BH, but in order to
> do so, I need to know exactly how the tree construction works. I'm
> having some troubles with what some variables or pointers stand for.
>
> In particular one of the pointers used in the function
> force_treebuild_single( ) during the insertion of particles is giving
> me a headache:
>
> th = DomainNodeIndex[no]
>
> I just can't get my finger on the values this "DomainNodeIndex[no]"
> can take. I presume the value of this pointer changes in such a way
> that the node selected for the particle insertion corresponds to the
> node at the correct level of the tree. But I can find the place were
> DomainNodeIndex[no] is asigned a value.
>
> Am I correct about the function of DomainNodeIndex[no] ?
Hi Aldo,
In fact all is described in allvars.h
In particular, for DomainNodeIndex, you can read :

 /*!< this table gives for each leaf of the top-level tree the
corresponding node of the gravitational tree */


so, in other words, this variable makes the link between the top-level
tree and the gravitational tree ;-) .

Cheers,

yves


>
> I really hope someone can give me a hint on this.
>
>
> Thanks in advance.
>
> Aldo Batta.
>
> --
>
> Instituto de Astronomia
> Universidad Nacional Autonoma de Mexico (UNAM)
> http://www.astroscu.unam.mx


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  Dr. Yves Revaz
  Laboratory of Astrophysics
  Ecole Polytechnique Fédérale de Lausanne (EPFL)
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Received on 2010-09-06 09:38:33

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