[petsc-users] Matrix format mpiaij does not have a built-in PETSc XXX!

[Aron Roland]

Dear All,

I hope somebody can help us on this or give at least some clearance.

We have just included PETSc as an solver for our sparse matrix evolving 
from an unstructured mesh advection scheme.

The problem is that we are using the mpiaij matrix type, since our 
matrix is naturally sparse. However it seems that PETSc has no PC for 
this, except the PCSOR, which showed to be not very effective for our 
problem.

All others give the error msg. of the mail subject, where XXX are the 
different PC tried.

The manual is a bit diffuse on this e.g.

http://www.mcs.anl.gov/petsc/documentation/linearsolvertable.html

it is claimed that certain PC's are running on aij matrices ... but 
these are to be defined either as seq. or parallel (mpiaij) matrices. 
Moreover in the above mentioned list are two columns parallel/seriel, 
what is the intention of parallel capability when not applicable to 
matrices stored within the parallel mpiaij framework.

I guess we just not understanding the concept or have some other 
difficulties of understanding of all this.

Any comments help is welcome

Aron