You should be able to. This behavior is the same as in PCASM, except in GASM the matrices live on subcommunicators. I am in transit right now, but I can take a closer look in Friday.
Dmitry On Feb 15, 2012, at 8:07, Hui Zhang <mike.hui.zhang at hotmail.com> wrote: > 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/20120215/386a675d/attachment-0001.htm>
