PETSC_EXTERN void PETSC_STDCALL pcshellsetdestroy_(PC *pc,void (PETSC_STDCALL *setup)(void*,PetscErrorCode*),PetscErrorCode *ierr) { PetscObjectAllocateFortranPointers(*pc,9); ((PetscObject)*pc)->fortran_func_pointers[5] = (PetscVoidFunction)setup; *ierr = PCShellSetDestroy(*pc,ourshelldestroy); }
int main(int argc, char **argv) { PetscErrorCode ierr; PetscInt n=10000,its,dfid=1; Vec x,b,u; Mat A; KSP ksp; PC pc,pcnoise; PCNoise_Ctx ctx={0,NULL}; PetscReal eta=0.1,norm; PetscScalar(*diagfunc)(PetscInt,PetscInt); ierr = PetscInitialize(&argc,&argv,(char*)0,help);CHKERRQ(ierr); /* Process command line options */ ierr = PetscOptionsGetInt(NULL,"-n",&n,NULL);CHKERRQ(ierr); ierr = PetscOptionsGetReal(NULL,"-eta",&eta,NULL);CHKERRQ(ierr); ierr = PetscOptionsGetInt(NULL,"-diagfunc",&dfid,NULL);CHKERRQ(ierr); switch(dfid){ case 1: diagfunc = diagFunc1; break; case 2: diagfunc = diagFunc2; break; case 3: diagfunc = diagFunc3; break; default: SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Unrecognized diagfunc option"); } /* Create a diagonal matrix with a given distribution of diagonal elements */ ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr); ierr = MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n);CHKERRQ(ierr); ierr = MatSetFromOptions(A);CHKERRQ(ierr); ierr = MatSetUp(A);CHKERRQ(ierr); ierr = AssembleDiagonalMatrix(A,diagfunc);CHKERRQ(ierr); /* Allocate vectors and manufacture an exact solution and rhs */ ierr = MatCreateVecs(A,&x,NULL);CHKERRQ(ierr); ierr = PetscObjectSetName((PetscObject)x,"Computed Solution");CHKERRQ(ierr); ierr = MatCreateVecs(A,&b,NULL);CHKERRQ(ierr); ierr = PetscObjectSetName((PetscObject)b,"RHS");CHKERRQ(ierr); ierr = MatCreateVecs(A,&u,NULL);CHKERRQ(ierr); ierr = PetscObjectSetName((PetscObject)u,"Reference Solution");CHKERRQ(ierr); ierr = VecSet(u,1.0);CHKERRQ(ierr); ierr = MatMult(A,u,b);CHKERRQ(ierr); /* Create a KSP object */ ierr = KSPCreate(PETSC_COMM_WORLD,&ksp);CHKERRQ(ierr); ierr = KSPSetOperators(ksp,A,A);CHKERRQ(ierr); /* Set up a composite preconditioner */ ierr = KSPGetPC(ksp,&pc);CHKERRQ(ierr); ierr = PCSetType(pc,PCCOMPOSITE);CHKERRQ(ierr); /* default composite with single Identity PC */ ierr = PCCompositeSetType(pc,PC_COMPOSITE_ADDITIVE);CHKERRQ(ierr); ierr = PCCompositeAddPC(pc,PCNONE);CHKERRQ(ierr); if(eta > 0){ ierr = PCCompositeAddPC(pc,PCSHELL);CHKERRQ(ierr); ierr = PCCompositeGetPC(pc,1,&pcnoise);CHKERRQ(ierr); ctx.eta = eta; ierr = PCShellSetContext(pcnoise,&ctx);CHKERRQ(ierr); ierr = PCShellSetApply(pcnoise,PCApply_Noise);CHKERRQ(ierr); ierr = PCShellSetSetUp(pcnoise,PCSetup_Noise);CHKERRQ(ierr); ierr = PCShellSetDestroy(pcnoise,PCDestroy_Noise);CHKERRQ(ierr); ierr = PCShellSetName(pcnoise,"Noise PC");CHKERRQ(ierr); } /* Set KSP from options (this can override the PC just defined) */ ierr = KSPSetFromOptions(ksp);CHKERRQ(ierr); /* Solve */ ierr = KSPSolve(ksp,b,x);CHKERRQ(ierr); /* Compute error */ ierr = VecAXPY(x,-1.0,u);CHKERRQ(ierr); ierr = PetscObjectSetName((PetscObject)x,"Error");CHKERRQ(ierr); ierr = VecNorm(x,NORM_2,&norm);CHKERRQ(ierr); ierr = KSPGetIterationNumber(ksp,&its);CHKERRQ(ierr); ierr = PetscPrintf(PETSC_COMM_WORLD,"Norm of error %g, Iterations %D\n",(double)norm,its);CHKERRQ(ierr); /* Destroy objects and finalize */ ierr = KSPDestroy(&ksp);CHKERRQ(ierr); ierr = MatDestroy(&A);CHKERRQ(ierr); ierr = VecDestroy(&x);CHKERRQ(ierr); ierr = VecDestroy(&b);CHKERRQ(ierr); ierr = VecDestroy(&u);CHKERRQ(ierr); PetscFinalize(); return 0; }
PetscErrorCode PCBDDCNullSpaceAssembleCorrection(PC pc, PetscBool isdir, IS local_dofs) { PC_BDDC *pcbddc = (PC_BDDC*)pc->data; PC_IS *pcis = (PC_IS*)pc->data; Mat_IS* matis = (Mat_IS*)pc->pmat->data; KSP local_ksp; PC newpc; NullSpaceCorrection_ctx shell_ctx; Mat local_mat,local_pmat,small_mat,inv_small_mat; Vec work1,work2; const Vec *nullvecs; VecScatter scatter_ctx; IS is_aux; MatFactorInfo matinfo; PetscScalar *basis_mat,*Kbasis_mat,*array,*array_mat; PetscScalar one = 1.0,zero = 0.0, m_one = -1.0; PetscInt basis_dofs,basis_size,nnsp_size,i,k; PetscBool nnsp_has_cnst; PetscErrorCode ierr; PetscFunctionBegin; /* Infer the local solver */ ierr = ISGetSize(local_dofs,&basis_dofs);CHKERRQ(ierr); if (isdir) { /* Dirichlet solver */ local_ksp = pcbddc->ksp_D; } else { /* Neumann solver */ local_ksp = pcbddc->ksp_R; } ierr = KSPGetOperators(local_ksp,&local_mat,&local_pmat);CHKERRQ(ierr); /* Get null space vecs */ ierr = MatNullSpaceGetVecs(pcbddc->NullSpace,&nnsp_has_cnst,&nnsp_size,&nullvecs);CHKERRQ(ierr); basis_size = nnsp_size; if (nnsp_has_cnst) { basis_size++; } if (basis_dofs) { /* Create shell ctx */ ierr = PetscNew(&shell_ctx);CHKERRQ(ierr); /* Create work vectors in shell context */ ierr = VecCreate(PETSC_COMM_SELF,&shell_ctx->work_small_1);CHKERRQ(ierr); ierr = VecSetSizes(shell_ctx->work_small_1,basis_size,basis_size);CHKERRQ(ierr); ierr = VecSetType(shell_ctx->work_small_1,VECSEQ);CHKERRQ(ierr); ierr = VecDuplicate(shell_ctx->work_small_1,&shell_ctx->work_small_2);CHKERRQ(ierr); ierr = VecCreate(PETSC_COMM_SELF,&shell_ctx->work_full_1);CHKERRQ(ierr); ierr = VecSetSizes(shell_ctx->work_full_1,basis_dofs,basis_dofs);CHKERRQ(ierr); ierr = VecSetType(shell_ctx->work_full_1,VECSEQ);CHKERRQ(ierr); ierr = VecDuplicate(shell_ctx->work_full_1,&shell_ctx->work_full_2);CHKERRQ(ierr); /* Allocate workspace */ ierr = MatCreateSeqDense(PETSC_COMM_SELF,basis_dofs,basis_size,NULL,&shell_ctx->basis_mat );CHKERRQ(ierr); ierr = MatCreateSeqDense(PETSC_COMM_SELF,basis_dofs,basis_size,NULL,&shell_ctx->Kbasis_mat);CHKERRQ(ierr); ierr = MatDenseGetArray(shell_ctx->basis_mat,&basis_mat);CHKERRQ(ierr); ierr = MatDenseGetArray(shell_ctx->Kbasis_mat,&Kbasis_mat);CHKERRQ(ierr); /* Restrict local null space on selected dofs (Dirichlet or Neumann) and compute matrices N and K*N */ ierr = VecDuplicate(shell_ctx->work_full_1,&work1);CHKERRQ(ierr); ierr = VecDuplicate(shell_ctx->work_full_1,&work2);CHKERRQ(ierr); ierr = VecScatterCreate(pcis->vec1_N,local_dofs,work1,(IS)0,&scatter_ctx);CHKERRQ(ierr); } for (k=0;k<nnsp_size;k++) { ierr = VecScatterBegin(matis->rctx,nullvecs[k],pcis->vec1_N,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); ierr = VecScatterEnd(matis->rctx,nullvecs[k],pcis->vec1_N,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); if (basis_dofs) { ierr = VecPlaceArray(work1,(const PetscScalar*)&basis_mat[k*basis_dofs]);CHKERRQ(ierr); ierr = VecScatterBegin(scatter_ctx,pcis->vec1_N,work1,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); ierr = VecScatterEnd(scatter_ctx,pcis->vec1_N,work1,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); ierr = VecPlaceArray(work2,(const PetscScalar*)&Kbasis_mat[k*basis_dofs]);CHKERRQ(ierr); ierr = MatMult(local_mat,work1,work2);CHKERRQ(ierr); ierr = VecResetArray(work1);CHKERRQ(ierr); ierr = VecResetArray(work2);CHKERRQ(ierr); } } if (basis_dofs) { if (nnsp_has_cnst) { ierr = VecPlaceArray(work1,(const PetscScalar*)&basis_mat[k*basis_dofs]);CHKERRQ(ierr); ierr = VecSet(work1,one);CHKERRQ(ierr); ierr = VecPlaceArray(work2,(const PetscScalar*)&Kbasis_mat[k*basis_dofs]);CHKERRQ(ierr); ierr = MatMult(local_mat,work1,work2);CHKERRQ(ierr); ierr = VecResetArray(work1);CHKERRQ(ierr); ierr = VecResetArray(work2);CHKERRQ(ierr); } ierr = VecDestroy(&work1);CHKERRQ(ierr); ierr = VecDestroy(&work2);CHKERRQ(ierr); ierr = VecScatterDestroy(&scatter_ctx);CHKERRQ(ierr); ierr = MatDenseRestoreArray(shell_ctx->basis_mat,&basis_mat);CHKERRQ(ierr); ierr = MatDenseRestoreArray(shell_ctx->Kbasis_mat,&Kbasis_mat);CHKERRQ(ierr); /* Assemble another Mat object in shell context */ ierr = MatTransposeMatMult(shell_ctx->basis_mat,shell_ctx->Kbasis_mat,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&small_mat);CHKERRQ(ierr); ierr = MatFactorInfoInitialize(&matinfo);CHKERRQ(ierr); ierr = ISCreateStride(PETSC_COMM_SELF,basis_size,0,1,&is_aux);CHKERRQ(ierr); ierr = MatLUFactor(small_mat,is_aux,is_aux,&matinfo);CHKERRQ(ierr); ierr = ISDestroy(&is_aux);CHKERRQ(ierr); ierr = PetscMalloc1(basis_size*basis_size,&array_mat);CHKERRQ(ierr); for (k=0;k<basis_size;k++) { ierr = VecSet(shell_ctx->work_small_1,zero);CHKERRQ(ierr); ierr = VecSetValue(shell_ctx->work_small_1,k,one,INSERT_VALUES);CHKERRQ(ierr); ierr = VecAssemblyBegin(shell_ctx->work_small_1);CHKERRQ(ierr); ierr = VecAssemblyEnd(shell_ctx->work_small_1);CHKERRQ(ierr); ierr = MatSolve(small_mat,shell_ctx->work_small_1,shell_ctx->work_small_2);CHKERRQ(ierr); ierr = VecGetArrayRead(shell_ctx->work_small_2,(const PetscScalar**)&array);CHKERRQ(ierr); for (i=0;i<basis_size;i++) { array_mat[i*basis_size+k]=array[i]; } ierr = VecRestoreArrayRead(shell_ctx->work_small_2,(const PetscScalar**)&array);CHKERRQ(ierr); } ierr = MatCreateSeqDense(PETSC_COMM_SELF,basis_size,basis_size,array_mat,&inv_small_mat);CHKERRQ(ierr); ierr = MatMatMult(shell_ctx->basis_mat,inv_small_mat,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&shell_ctx->Lbasis_mat);CHKERRQ(ierr); ierr = PetscFree(array_mat);CHKERRQ(ierr); ierr = MatDestroy(&inv_small_mat);CHKERRQ(ierr); ierr = MatDestroy(&small_mat);CHKERRQ(ierr); ierr = MatScale(shell_ctx->Kbasis_mat,m_one);CHKERRQ(ierr); /* Rebuild local PC */ ierr = KSPGetPC(local_ksp,&shell_ctx->local_pc);CHKERRQ(ierr); ierr = PetscObjectReference((PetscObject)shell_ctx->local_pc);CHKERRQ(ierr); ierr = PCCreate(PETSC_COMM_SELF,&newpc);CHKERRQ(ierr); ierr = PCSetOperators(newpc,local_mat,local_mat);CHKERRQ(ierr); ierr = PCSetType(newpc,PCSHELL);CHKERRQ(ierr); ierr = PCShellSetContext(newpc,shell_ctx);CHKERRQ(ierr); ierr = PCShellSetApply(newpc,PCBDDCApplyNullSpaceCorrectionPC);CHKERRQ(ierr); ierr = PCShellSetDestroy(newpc,PCBDDCDestroyNullSpaceCorrectionPC);CHKERRQ(ierr); ierr = PCSetUp(newpc);CHKERRQ(ierr); ierr = KSPSetPC(local_ksp,newpc);CHKERRQ(ierr); ierr = PCDestroy(&newpc);CHKERRQ(ierr); ierr = KSPSetUp(local_ksp);CHKERRQ(ierr); } /* test */ if (pcbddc->dbg_flag && basis_dofs) { KSP check_ksp; PC check_pc; Mat test_mat; Vec work3; PetscReal test_err,lambda_min,lambda_max; PetscBool setsym,issym=PETSC_FALSE; PetscInt tabs; ierr = PetscViewerASCIIGetTab(pcbddc->dbg_viewer,&tabs);CHKERRQ(ierr); ierr = KSPGetPC(local_ksp,&check_pc);CHKERRQ(ierr); ierr = VecDuplicate(shell_ctx->work_full_1,&work1);CHKERRQ(ierr); ierr = VecDuplicate(shell_ctx->work_full_1,&work2);CHKERRQ(ierr); ierr = VecDuplicate(shell_ctx->work_full_1,&work3);CHKERRQ(ierr); ierr = VecSetRandom(shell_ctx->work_small_1,NULL);CHKERRQ(ierr); ierr = MatMult(shell_ctx->basis_mat,shell_ctx->work_small_1,work1);CHKERRQ(ierr); ierr = VecCopy(work1,work2);CHKERRQ(ierr); ierr = MatMult(local_mat,work1,work3);CHKERRQ(ierr); ierr = PCApply(check_pc,work3,work1);CHKERRQ(ierr); ierr = VecAXPY(work1,m_one,work2);CHKERRQ(ierr); ierr = VecNorm(work1,NORM_INFINITY,&test_err);CHKERRQ(ierr); ierr = PetscViewerASCIISynchronizedPrintf(pcbddc->dbg_viewer,"Subdomain %04d error for nullspace correction for ",PetscGlobalRank);CHKERRQ(ierr); ierr = PetscViewerASCIIUseTabs(pcbddc->dbg_viewer,PETSC_FALSE);CHKERRQ(ierr); if (isdir) { ierr = PetscViewerASCIISynchronizedPrintf(pcbddc->dbg_viewer,"Dirichlet ");CHKERRQ(ierr); } else { ierr = PetscViewerASCIISynchronizedPrintf(pcbddc->dbg_viewer,"Neumann ");CHKERRQ(ierr); } ierr = PetscViewerASCIISynchronizedPrintf(pcbddc->dbg_viewer,"solver is :%1.14e\n",test_err);CHKERRQ(ierr); ierr = PetscViewerASCIISetTab(pcbddc->dbg_viewer,tabs);CHKERRQ(ierr); ierr = PetscViewerASCIIUseTabs(pcbddc->dbg_viewer,PETSC_TRUE);CHKERRQ(ierr); ierr = MatTransposeMatMult(shell_ctx->Lbasis_mat,shell_ctx->Kbasis_mat,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&test_mat);CHKERRQ(ierr); ierr = MatShift(test_mat,one);CHKERRQ(ierr); ierr = MatNorm(test_mat,NORM_INFINITY,&test_err);CHKERRQ(ierr); ierr = MatDestroy(&test_mat);CHKERRQ(ierr); ierr = PetscViewerASCIISynchronizedPrintf(pcbddc->dbg_viewer,"Subdomain %04d error for nullspace matrices is :%1.14e\n",PetscGlobalRank,test_err);CHKERRQ(ierr); /* Create ksp object suitable for extreme eigenvalues' estimation */ ierr = KSPCreate(PETSC_COMM_SELF,&check_ksp);CHKERRQ(ierr); ierr = KSPSetErrorIfNotConverged(check_ksp,pc->erroriffailure);CHKERRQ(ierr); ierr = KSPSetOperators(check_ksp,local_mat,local_mat);CHKERRQ(ierr); ierr = KSPSetTolerances(check_ksp,1.e-8,1.e-8,PETSC_DEFAULT,basis_dofs);CHKERRQ(ierr); ierr = KSPSetComputeSingularValues(check_ksp,PETSC_TRUE);CHKERRQ(ierr); ierr = MatIsSymmetricKnown(pc->pmat,&setsym,&issym);CHKERRQ(ierr); if (issym) { ierr = KSPSetType(check_ksp,KSPCG);CHKERRQ(ierr); } ierr = KSPSetPC(check_ksp,check_pc);CHKERRQ(ierr); ierr = KSPSetUp(check_ksp);CHKERRQ(ierr); ierr = VecSetRandom(work1,NULL);CHKERRQ(ierr); ierr = MatMult(local_mat,work1,work2);CHKERRQ(ierr); ierr = KSPSolve(check_ksp,work2,work2);CHKERRQ(ierr); ierr = VecAXPY(work2,m_one,work1);CHKERRQ(ierr); ierr = VecNorm(work2,NORM_INFINITY,&test_err);CHKERRQ(ierr); ierr = KSPComputeExtremeSingularValues(check_ksp,&lambda_max,&lambda_min);CHKERRQ(ierr); ierr = KSPGetIterationNumber(check_ksp,&k);CHKERRQ(ierr); ierr = PetscViewerASCIISynchronizedPrintf(pcbddc->dbg_viewer,"Subdomain %04d error for adapted KSP %1.14e (it %d, eigs %1.6e %1.6e)\n",PetscGlobalRank,test_err,k,lambda_min,lambda_max);CHKERRQ(ierr); ierr = KSPDestroy(&check_ksp);CHKERRQ(ierr); ierr = VecDestroy(&work1);CHKERRQ(ierr); ierr = VecDestroy(&work2);CHKERRQ(ierr); ierr = VecDestroy(&work3);CHKERRQ(ierr); } /* all processes shoud call this, even the void ones */ if (pcbddc->dbg_flag) { ierr = PetscViewerFlush(pcbddc->dbg_viewer);CHKERRQ(ierr); } PetscFunctionReturn(0); }
int main(int argc,char **argv) { DMMG *dmmg; /* multilevel grid structure */ PetscErrorCode ierr; DA da; AppCtx app; PC pc; KSP ksp; PetscTruth isshell; PetscViewer v1; PetscInitialize(&argc,&argv,(char *)0,help); PreLoadBegin(PETSC_TRUE,"SetUp"); app.comm = PETSC_COMM_WORLD; app.nxv = 6; app.nyvf = 3; app.nyv = app.nyvf + 2; ierr = PetscOptionsBegin(app.comm,PETSC_NULL,"Options for Grid Sizes",PETSC_NULL); ierr = PetscOptionsInt("-nxv","Grid spacing in X direction",PETSC_NULL,app.nxv,&app.nxv,PETSC_NULL); CHKERRQ(ierr); ierr = PetscOptionsInt("-nyvf","Grid spacing in Y direction of Fuel",PETSC_NULL,app.nyvf,&app.nyvf,PETSC_NULL); CHKERRQ(ierr); ierr = PetscOptionsInt("-nyv","Total Grid spacing in Y direction of",PETSC_NULL,app.nyv,&app.nyv,PETSC_NULL); CHKERRQ(ierr); ierr = PetscOptionsEnd(); ierr = PetscViewerDrawOpen(app.comm,PETSC_NULL,"",-1,-1,-1,-1,&v1); CHKERRQ(ierr); /* Create the DMComposite object to manage the three grids/physics. We use a 1d decomposition along the y direction (since one of the grids is 1d). */ ierr = DMCompositeCreate(app.comm,&app.pack); CHKERRQ(ierr); /* 6 fluid unknowns, 3 ghost points on each end for either periodicity or simply boundary conditions */ ierr = DACreate1d(app.comm,DA_XPERIODIC,app.nxv,6,3,0,&da); CHKERRQ(ierr); ierr = DASetFieldName(da,0,"prss"); CHKERRQ(ierr); ierr = DASetFieldName(da,1,"ergg"); CHKERRQ(ierr); ierr = DASetFieldName(da,2,"ergf"); CHKERRQ(ierr); ierr = DASetFieldName(da,3,"alfg"); CHKERRQ(ierr); ierr = DASetFieldName(da,4,"velg"); CHKERRQ(ierr); ierr = DASetFieldName(da,5,"velf"); CHKERRQ(ierr); ierr = DMCompositeAddDM(app.pack,(DM)da); CHKERRQ(ierr); ierr = DADestroy(da); CHKERRQ(ierr); ierr = DACreate2d(app.comm,DA_YPERIODIC,DA_STENCIL_STAR,app.nxv,app.nyv,PETSC_DETERMINE,1,1,1,0,0,&da); CHKERRQ(ierr); ierr = DASetFieldName(da,0,"Tempature"); CHKERRQ(ierr); ierr = DMCompositeAddDM(app.pack,(DM)da); CHKERRQ(ierr); ierr = DADestroy(da); CHKERRQ(ierr); ierr = DACreate2d(app.comm,DA_XYPERIODIC,DA_STENCIL_STAR,app.nxv,app.nyvf,PETSC_DETERMINE,1,2,1,0,0,&da); CHKERRQ(ierr); ierr = DASetFieldName(da,0,"Phi"); CHKERRQ(ierr); ierr = DASetFieldName(da,1,"Pre"); CHKERRQ(ierr); ierr = DMCompositeAddDM(app.pack,(DM)da); CHKERRQ(ierr); ierr = DADestroy(da); CHKERRQ(ierr); app.pri = 1.0135e+5; app.ugi = 2.5065e+6; app.ufi = 4.1894e+5; app.agi = 1.00e-1; app.vgi = 1.0e-1 ; app.vfi = 1.0e-1; app.prin = 1.0135e+5; app.ugin = 2.5065e+6; app.ufin = 4.1894e+5; app.agin = 1.00e-1; app.vgin = 1.0e-1 ; app.vfin = 1.0e-1; app.prout = 1.0135e+5; app.ugout = 2.5065e+6; app.ufout = 4.1894e+5; app.agout = 3.0e-1; app.twi = 373.15e+0; app.phii = 1.0e+0; app.prei = 1.0e-5; /* Create the solver object and attach the grid/physics info */ ierr = DMMGCreate(app.comm,1,0,&dmmg); CHKERRQ(ierr); ierr = DMMGSetDM(dmmg,(DM)app.pack); CHKERRQ(ierr); ierr = DMMGSetUser(dmmg,0,&app); CHKERRQ(ierr); ierr = DMMGSetISColoringType(dmmg,IS_COLORING_GLOBAL); CHKERRQ(ierr); CHKMEMQ; ierr = DMMGSetInitialGuess(dmmg,FormInitialGuess); CHKERRQ(ierr); ierr = DMMGSetSNES(dmmg,FormFunction,0); CHKERRQ(ierr); ierr = DMMGSetFromOptions(dmmg); CHKERRQ(ierr); /* Supply custom shell preconditioner if requested */ ierr = SNESGetKSP(DMMGGetSNES(dmmg),&ksp); CHKERRQ(ierr); ierr = KSPGetPC(ksp,&pc); CHKERRQ(ierr); ierr = PetscTypeCompare((PetscObject)pc,PCSHELL,&isshell); CHKERRQ(ierr); if (isshell) { ierr = PCShellSetContext(pc,&app); CHKERRQ(ierr); ierr = PCShellSetSetUp(pc,MyPCSetUp); CHKERRQ(ierr); ierr = PCShellSetApply(pc,MyPCApply); CHKERRQ(ierr); ierr = PCShellSetDestroy(pc,MyPCDestroy); CHKERRQ(ierr); } /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Solve the nonlinear system - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ PreLoadStage("Solve"); ierr = DMMGSolve(dmmg); CHKERRQ(ierr); ierr = VecView(DMMGGetx(dmmg),v1); CHKERRQ(ierr); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Free work space. All PETSc objects should be destroyed when they are no longer needed. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = PetscViewerDestroy(v1); CHKERRQ(ierr); ierr = DMCompositeDestroy(app.pack); CHKERRQ(ierr); ierr = DMMGDestroy(dmmg); CHKERRQ(ierr); PreLoadEnd(); ierr = PetscFinalize(); CHKERRQ(ierr); return 0; }