Certainly it would be better to get a few more sweeps of SOR within the
BAM solver, but a better thing to try first would be to trun the SOR
solver prior to the BAM solver.  You will lose some efficiency in
running SOR after BAM, but you may have more high frequency noise in
there this way too.

-John


Project ELLIPTIC/Mark Miller wrote:
>   
>  Elliptic dudes (esp. Bernd), 
>   
>  I am using BAM to implement maximal slicing for 2 NS runs. 
>  However, BAM seems to give bad high frequency noise, as seen 
>  by this snapshot of trK along the x line, which 
>  is the axis joining the center of the 2 neutron stars (trK_ns.gif). 
>   
>  Wai-Mo remembered that I did a high-resolution run with misner 
>  BH data, and we see the same thing (high frequency noise getting 
>  worse in time).  Again, this is using maximal slicing with BAM. 
>  (trK_misner.gif). 
>   
>  I notice in the 2 NS case, the trK is much smoother when using 
>  SOR.  My question:  Bernd, is there any way to make BAM 
>  spend more time at the top of the V cycle?  That is, do 
>  a few more sweeps on the fine grid?  Or shall we code up 
>   
>  maximal = "bam-sor" 
>   
>  that would call bam as a preconditioner to SOR? 
>   
>  Mark 
>   
>  ------------------------------------------------ 
>  Mark Miller 
>  Department of Physics 
>  Washington University 
>  St. Louis, MO  63130-4899 
>  E-mail: mamiller@wugrav.wustl.edu 
>  office phone: (314) 935-4617,  fax: (314) 935-6219 
>  ------------------------------------------------ 
>   
>     [1][LINK]Filename: trK_ns.gif 
>     Size :57329 
>   
>     [2][LINK]Filename: trK_misner.gif 
>     Size :83717 
>   
>  References 
>   
>     1. file://localhost/home2/web/Util/projects/trK_ns.gif 
>     2. file://localhost/home2/web/Util/projects/trK_misner.gif 
>  _______________________________________________________________________ 
>   
>  CoCoBoard Information: 
>    From: Mark Miller  <mamiller@void.wustl.edu> 
>    URL : http://wugrav.wustl.edu/Util/projects/ELLIPTIC/00022/ 
>   
>  Cross-Posted to: NS_ELLIPTIC,ELLIPTIC 

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