[Carpet] Prolongation order

[Erik Schnetter]

On Apr 3, 2008, at 10:57:30, Ian Hinder wrote:
> Erik Schnetter wrote:
>> On Apr 3, 2008, at 10:28:02, Ian Hinder wrote:
>>> But from your description above, I would have thought the number of
>>> ghost zones required would be 2 for the 5th order stencil, but
>>> (prolongation_order_space+1)/2 gives 3?
>>
>> A 5th order stencil (where "5" is counted according to Carpet
>> conventions) requires 6 points, hence 3 the stencil radius is 3.
>
> o o o o o o o o o o o o o o o o o
>              |
> X  (X) (X) (X) (X) (X) (X)  X   X
>
> So in principle, Carpet picks one of the adjacent coarse points to the
> fine point it wants to interpolate, and identifies which processor  
> it is
> on.  That processor is then asked to interpolate, which requires it to
> have all six points, meaning that at least in one of the directions,
> three additional points are required.  OK - getting clearer!


Yes, exactly.

-erik

-- 
Erik Schnetter <schnetter at cct.lsu.edu>   http://www.cct.lsu.edu/~eschnett/

My email is as private as my paper mail.  I therefore support encrypting
and signing email messages.  Get my PGP key from www.keyserver.net.



-------------- next part --------------
A non-text attachment was scrubbed...
Name: PGP.sig
Type: application/pgp-signature
Size: 194 bytes
Desc: This is a digitally signed message part
Url : /archives/developers/attachments/20080403/949e4da2/attachment.pgp