[Gmsh] Meaning of Ghost Cell

Daniel Wheeler daniel.wheeler2 at gmail.com
Mon Jul 2 15:37:11 CEST 2012


On Fri, Jun 29, 2012 at 1:55 PM, Orhan Shibliyev <orxan.shibli at gmail.com>wrote:

> Hi all****
>
> ** **
>
> I took a look at the GMSH reference manual to understand what a ghost cell
> is but did not find any explanation. Could someone tell me what that means?
>

A ghost cell generally refers to a cell that exists on more than one
partition and has the same physical location on both partitions, it is
referred to as a ghost cell on one of the partitions, but is used as a
regular cell on the other partition (i.e. a solution is calculated for that
cell).


> Also how a cell can belong to more than one partition?
>


Most solutions in parallel require data from neighboring partitions. A
ghost cell knows its local ID on both partitions (and obviously which
partitions it belongs to) giving the program that reads the mesh file
enough information to deal with the communication issues.



> Should not it belong to only one partition?
>

It wouldn't be much use if it only belonged to one partition.


-- 
Daniel Wheeler
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