> Il giorno 24 feb 2020, alle ore 12:08, Mark Adams <mfad...@lbl.gov> ha > scritto: > > > On Mon, Feb 24, 2020 at 5:30 AM Pierpaolo Minelli <pierpaolo.mine...@cnr.it > <mailto:pierpaolo.mine...@cnr.it>> wrote: > Hi, > I'm developing a 3D code in Fortran to study the space-time evolution of > charged particles within a Cartesian domain. > The domain decomposition has been made by me taking into account symmetry and > load balancing reasons related to my specific problem. In this first draft, > it will remain constant throughout my simulation. > > Is there a way, using DMDAs, to solve Poisson's equation, using the domain > decomposition above, obtaining as a result the local solution including its > ghost cells values? > > https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/DM/DMGlobalToLocalBegin.html#DMGlobalToLocalBegin > > <https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/DM/DMGlobalToLocalBegin.html#DMGlobalToLocalBegin> > > > > As input data at each time-step I know the electric charge density in each > local subdomain (RHS), including the ghost cells, even if I don't think they > are useful for the calculation of the equation. > Matrix coefficients (LHS) and boundary conditions are constant during my > simulation. > > As an output I would need to know the local electrical potential in each > local subdomain, including the values of the ghost cells in each > dimension(X,Y,Z). > > Is there an example that I can use in Fortran to solve this kind of problem? > > I see one, but it is not hard to convert a C example: > > https://www.mcs.anl.gov/petsc/petsc-current/src/ksp/ksp/examples/tutorials/ex14f.F90.html > > <https://www.mcs.anl.gov/petsc/petsc-current/src/ksp/ksp/examples/tutorials/ex14f.F90.html>
Thanks, i will try to give a look to this example and i will try to check also C examples in that directory. > > > Thanks in advance > > Pierpaolo Minelli >
