[petsc-users] Partitioning and AO problem

[Jed Brown]

"Miguel A. Fernández" <miguel.fernandez at inria.fr> writes:

> Dear all,
>
> I'm using Petsc interface to ParMetis, as detailed in section 3.5 of the user's manual.
>
> I have a problem with the creation of the AO mapps using the sentence 
>
> AOCreateBasicIS(isg,PETSC NULL,&ao);

This line in the user's manual is incorrect. See Section 2.3.1 for a
proper explanation.

> where isg contains for each local node the new global (petsc) number of that node.
> The problem is that the resulting AO map is inverted, and hence the results obtained with 
> AOApplicationToPetsc and AOPetscToApplication are not correct. 

You have the arguments backward.

http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/AO/AOCreateBasic.html

It's not clear from your description above whether you have an
"application ordering" or just a local to global map.