On Feb 15, 2012, at 11:19 AM, Hui Zhang wrote: > Hi Dmitry, > > thanks a lot! Currently, I'm not using ISColoring. Just comes another question > on PCGASMSetModifySubMatrices(). The user provided function has the prototype > > func (PC pc,PetscInt nsub,IS *row,IS *col,Mat *submat,void *ctx); > > I think the coloumns from the parameter 'col' are always the same as the rows > from the parameter 'row'. Because PCGASMSetLocalSubdomains() only accepts > index sets but not rows and columns. Has I misunderstood something?
As I tested, the row and col are always the same. I have a new question. Am I allowed to SetLocalToGlobalMapping() for the submat's in the above func()? thanks, Hui > > thanks, > Hui > > > On Feb 11, 2012, at 3:36 PM, Dmitry Karpeev wrote: > >> Yes, that's right. >> There is no good way to help the user assemble the subdomains at the moment >> beyond the 2D stuff. >> It is expected that they are generated from mesh subdomains. >> Each IS does carry the subdomains subcomm. >> >> There is ISColoringToList() that is supposed to convert a "coloring" of >> indices to an array of ISs, >> each having the indices with the same color and the subcomm that supports >> that color. It is >> largely untested, though. You could try using it and give us feedback on >> any problems you encounter. >> >> Dmitry. >> >> >> On Sat, Feb 11, 2012 at 6:06 AM, Hui Zhang <mike.hui.zhang at hotmail.com> >> wrote: >> About PCGASMSetLocalSubdomains(), in the case of one subdomain supported by >> multiple processors, shall I always create the arguments 'is[s]' and >> 'is_local[s]' >> in a subcommunicator consisting of processors supporting the subdomain 's'? >> >> The source code of PCGASMCreateSubdomains2D() seemingly does so. >> >> Thanks, >> Hui >> >> > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120215/1b3442b6/attachment.htm>
