int main(int argc,char **argv)
{
PetscErrorCode ierr;
KSP ksp;
PetscReal norm;
DM da;
Vec x,b,r;
Mat A;
ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
ierr = KSPCreate(PETSC_COMM_WORLD,&ksp);CHKERRQ(ierr);
ierr = DMDACreate3d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_STAR,7,7,7,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,1,1,0,0,0,&da);CHKERRQ(ierr);
ierr = DMSetFromOptions(da);CHKERRQ(ierr);
ierr = DMSetUp(da);CHKERRQ(ierr);
ierr = KSPSetDM(ksp,da);CHKERRQ(ierr);
ierr = KSPSetComputeInitialGuess(ksp,ComputeInitialGuess,NULL);CHKERRQ(ierr);
ierr = KSPSetComputeRHS(ksp,ComputeRHS,NULL);CHKERRQ(ierr);
ierr = KSPSetComputeOperators(ksp,ComputeMatrix,NULL);CHKERRQ(ierr);
ierr = DMDestroy(&da);CHKERRQ(ierr);
ierr = KSPSetFromOptions(ksp);CHKERRQ(ierr);
ierr = KSPSolve(ksp,NULL,NULL);CHKERRQ(ierr);
ierr = KSPGetSolution(ksp,&x);CHKERRQ(ierr);
ierr = KSPGetRhs(ksp,&b);CHKERRQ(ierr);
ierr = VecDuplicate(b,&r);CHKERRQ(ierr);
ierr = KSPGetOperators(ksp,&A,NULL);CHKERRQ(ierr);
ierr = MatMult(A,x,r);CHKERRQ(ierr);
ierr = VecAXPY(r,-1.0,b);CHKERRQ(ierr);
ierr = VecNorm(r,NORM_2,&norm);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Residual norm %g\n",(double)norm);CHKERRQ(ierr);
ierr = VecDestroy(&r);CHKERRQ(ierr);
ierr = KSPDestroy(&ksp);CHKERRQ(ierr);
ierr = PetscFinalize();
return ierr;
}
PetscErrorCode efs_setup(efs *slv, int offset[], int stride[])
{
PetscErrorCode ierr;
PetscInt xs, ys, zs, xm, ym, zm;
PCType pc_type;
if (efs_log(slv, EFS_LOG_STATUS)) {
ierr = ef_io_print(slv->comm, "Setting up electric field solver");CHKERRQ(ierr);
}
slv->ts = 0;
if (efs_log(slv, EFS_LOG_RESIDUAL)) {
ierr = PetscOptionsSetValue("-ksp_monitor_short", NULL);CHKERRQ(ierr);
}
ierr = DMDASetFieldName(slv->dm, 0,"potential");CHKERRQ(ierr);
if (slv->grid.nd == 2) {
ierr = DMDAGetCorners(slv->dm, &xs, &ys, 0, &xm, &ym, 0);CHKERRQ(ierr);
slv->dmap = ef_dmap_create_2d(xs - offset[0], ys - offset[1], xm, ym, stride);
} else if (slv->grid.nd == 3) {
ierr = DMDAGetCorners(slv->dm, &xs, &ys, &zs, &xm, &ym, &zm);CHKERRQ(ierr);
slv->dmap = ef_dmap_create_3d(xs - offset[0], ys - offset[1], zs - offset[2], xm, ym, zm, stride);
} else {
SETERRQ1(PETSC_COMM_WORLD, PETSC_ERR_SUP, "Unsupported dimmension: %d", slv->grid.nd);
}
ierr = ef_callback_create(&slv->callback);CHKERRQ(ierr);
ierr = KSPCreate(slv->comm, &slv->ksp);CHKERRQ(ierr);
if (efs_log(slv, EFS_LOG_EIGS)) {
ierr = KSPSetComputeEigenvalues(slv->ksp, PETSC_TRUE);CHKERRQ(ierr);
}
ierr = KSPSetDM(slv->ksp, slv->dm);CHKERRQ(ierr);
ierr = KSPGetPC(slv->ksp, &slv->pc);CHKERRQ(ierr);
ierr = PCSetType(slv->pc, PCMG);CHKERRQ(ierr);
if (slv->options.galerkin) {
ierr = PCMGSetGalerkin(slv->pc, PETSC_TRUE);CHKERRQ(ierr);
} else {
ierr = PCMGSetGalerkin(slv->pc, PETSC_FALSE);CHKERRQ(ierr);
}
ierr = KSPSetComputeOperators(slv->ksp, slv->callback->matrix, slv);CHKERRQ(ierr);
ierr = KSPSetComputeRHS(slv->ksp, slv->callback->rhs, slv);CHKERRQ(ierr);
ierr = KSPSetComputeInitialGuess(slv->ksp, slv->callback->guess, slv);CHKERRQ(ierr);
ierr = KSPSetFromOptions(slv->ksp);CHKERRQ(ierr);
ierr = PCGetType(slv->pc, &pc_type);CHKERRQ(ierr);
ierr = PCMGGetLevels(slv->pc, &slv->options.levels);CHKERRQ(ierr);
if (slv->options.levels < 1) slv->options.levels++;
ierr = PCMGGetGalerkin(slv->pc, &slv->options.galerkin);CHKERRQ(ierr);
if (strcmp(pc_type, PCGAMG) == 0
|| strcmp(pc_type, PCHYPRE) == 0) slv->options.galerkin = 1;
if (!slv->options.galerkin) {
slv->levels = (ef_level*) malloc(slv->options.levels*sizeof(ef_level));
// setup callback for transforming rhs on coarse levels
} else {
slv->levels = (ef_level*) malloc(sizeof(ef_level));
}
ierr = ef_fd_create(&slv->fd, EF_FD_STANDARD_O2);CHKERRQ(ierr);
ierr = ef_operator_create(&slv->op, slv->levels, slv->fd, slv->grid.nd);CHKERRQ(ierr);
ierr = ef_boundary_create(&slv->boundary, slv->levels, slv->options.levels,
slv->dmap, &slv->state, slv->fd);CHKERRQ(ierr);
slv->op->axisymmetric = slv->options.axisymmetric;
slv->boundary->axisymmetric = slv->options.axisymmetric;
ierr = DMSetMatType(slv->dm, MATAIJ);CHKERRQ(ierr);
ierr = DMCreateGlobalVector(slv->dm, &slv->levels[0].eps);CHKERRQ(ierr);
ierr = DMCreateGlobalVector(slv->dm, &slv->levels[0].g);CHKERRQ(ierr);
ierr = DMCreateGlobalVector(slv->dm, &slv->levels[0].ag);CHKERRQ(ierr);
ierr = DMCreateGlobalVector(slv->dm, &slv->levels[0].gcomp);CHKERRQ(ierr);
ierr = DMCreateGlobalVector(slv->dm, &slv->levels[0].scale);CHKERRQ(ierr);
ierr = DMCreateGlobalVector(slv->dm, &slv->levels[0].nscale);CHKERRQ(ierr);
ierr = VecSet(slv->levels[0].g, 0);CHKERRQ(ierr);
ierr = VecSet(slv->levels[0].gcomp, 1);CHKERRQ(ierr);
ierr = VecSet(slv->levels[0].scale, 1);CHKERRQ(ierr);
ierr = VecSet(slv->levels[0].nscale, 1);CHKERRQ(ierr);
ierr = DMCoarsenHookAdd(slv->dm, slv->callback->coarsen, slv->callback->restrct, slv);CHKERRQ(ierr);
return 0;
}
