[petsc-dev] DMDA_*PERIODIC and DMDA_XYZGHOSTED

[Ethan Coon]

> 
> I think I prefer
> 
> enum {
> NONPERIODIC = 0,
> XGHOSTED = 0x1,
> XPERIODIC = 0x3,
> YGHOSTED = 0x4,
> YPERIODIC = 0xc,
> ZGHOSTED = 0x10,
> ZPERIODIC = 0x11,
> }
> 
> 
> DMDACreate3D(...,XPERIODIC | YGHOSTED,...).
> 

This sounds good to me, and much cleaner to evaluate as well.  

Ethan


> 
> would produce periodic in X, ghosted in Y, and no endpoint ghosts (but
> still internal neighbors) in Z.
> 
> 
> If you really wanted, you could
> 
> 
> #define DMDA_YZPERIODIC (DMDA_YPERIODIC | DMDA_ZPERIODIC)
> 
> 
> but I don't think it's a big deal (users can do that if they want, but
> it's working around an awkward initial API choice).
> 
> 
> Handling anisotropic stencil width would be useful for some problems,
> but it's a much bigger effort.
> 
> 
> Jed

-- 
-------------------------------------
Ethan Coon
Post-Doctoral Researcher
Mathematical Modeling and Analysis
Los Alamos National Laboratory
505-665-8289

http://www.ldeo.columbia.edu/~ecoon/
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