[petsc-users] petsc with slepc

[Jose E. Roman]

On 07/09/2011, Micheal Lysaght wrote:

> 
> Dear PETSc team,
> 
> I am currently using PETSc with SLEPc to diagonalize a sparse Hermitian matrix. I have had success with doing so, so long as I create the PETSc matrix object using
> 
> MatCreateMPISBAIJ
> 
> with PETSC_DECIDE used for both the number of rows and columns.
> 
> Upon assembling the matrix object, I then call the relevant SLEPc EPS routines (where the default Krylov Schur method is invoked)
> 
> Doing this, everything works fine and the correct eigenvalues are returned.
> 
> However, if I try to do the same thing with the difference that I decide the number of rows and columns assigned to each MPI process during the matrix creation, SLEPc returns an error message with regard to the dimensions being used.
> 
> I have checked that the matrix object has the correct form and values by viewing the matrix, so it is certainly assembled in the correct way using PETSc.
> 
> My question is, can SLEPc handle matrices that are constructed according to the users choice of the numbers of rows and columns assigned to each MPI process. I realize that this would need to be accounted for in the vector that is being multiplied into, but how do I get access to this vector in SLEPc? Or do I even need to?
> 
> Any help or tips would be very much appreciated.
> 
> Best regards,
> 
> Michael Lysaght
> Visiting Research Fellow,
> CTAMOP,
> Queen's University Belfast

Send the complete error message. Also, if you can reproduce the problem in a simple example, send it to slepc-maint at grycap.upv.es and we will give it a try.

Jose