int main(int argc,char **args) { Mat C,A; PetscInt i,j; PetscErrorCode ierr; PetscScalar v; PC pc; Vec xtmp; ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr; ierr = MatCreate(PETSC_COMM_WORLD,&C);CHKERRQ(ierr); ierr = MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,3,3);CHKERRQ(ierr); ierr = MatSetFromOptions(C);CHKERRQ(ierr); ierr = MatSetUp(C);CHKERRQ(ierr); ierr = VecCreateSeq(PETSC_COMM_WORLD,3,&xtmp);CHKERRQ(ierr); i = 0; j = 0; v = 4; ierr = MatSetValues(C,1,&i,1,&j,&v,INSERT_VALUES);CHKERRQ(ierr); i = 0; j = 2; v = 1; ierr = MatSetValues(C,1,&i,1,&j,&v,INSERT_VALUES);CHKERRQ(ierr); i = 1; j = 0; v = 1; ierr = MatSetValues(C,1,&i,1,&j,&v,INSERT_VALUES);CHKERRQ(ierr); i = 1; j = 1; v = 4; ierr = MatSetValues(C,1,&i,1,&j,&v,INSERT_VALUES);CHKERRQ(ierr); i = 2; j = 1; v = 1; ierr = MatSetValues(C,1,&i,1,&j,&v,INSERT_VALUES);CHKERRQ(ierr); ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); ierr = MatView(C,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); ierr = PCCreate(PETSC_COMM_WORLD,&pc);CHKERRQ(ierr); ierr = PCSetFromOptions(pc);CHKERRQ(ierr); ierr = PCSetOperators(pc,C,C);CHKERRQ(ierr); ierr = PCSetUp(pc);CHKERRQ(ierr); ierr = PCFactorGetMatrix(pc,&A);CHKERRQ(ierr); ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); ierr = PCDestroy(&pc);CHKERRQ(ierr); ierr = VecDestroy(&xtmp);CHKERRQ(ierr); ierr = MatDestroy(&C);CHKERRQ(ierr); ierr = PetscFinalize(); return ierr; }
int main(int argc,char **argv) { KSP ksp; PC pc; Mat A,M; Vec X,B,D; MPI_Comm comm; PetscScalar v; KSPConvergedReason reason; PetscInt i,j,its; PetscErrorCode ierr; PetscFunctionBegin; ierr = PetscInitialize(&argc,&argv,0,help);CHKERRQ(ierr); ierr = PetscOptionsSetValue("-options_left",PETSC_NULL);CHKERRQ(ierr); comm = MPI_COMM_SELF; /* * Construct the Kershaw matrix * and a suitable rhs / initial guess */ ierr = MatCreateSeqAIJ(comm,4,4,4,0,&A);CHKERRQ(ierr); ierr = VecCreateSeq(comm,4,&B);CHKERRQ(ierr); ierr = VecDuplicate(B,&X);CHKERRQ(ierr); for (i=0; i<4; i++) { v=3; ierr = MatSetValues(A,1,&i,1,&i,&v,INSERT_VALUES);CHKERRQ(ierr); v=1; ierr = VecSetValues(B,1,&i,&v,INSERT_VALUES);CHKERRQ(ierr); ierr = VecSetValues(X,1,&i,&v,INSERT_VALUES);CHKERRQ(ierr); } i=0; v=0; ierr = VecSetValues(X,1,&i,&v,INSERT_VALUES);CHKERRQ(ierr); for (i=0; i<3; i++) { v=-2; j=i+1; ierr = MatSetValues(A,1,&i,1,&j,&v,INSERT_VALUES);CHKERRQ(ierr); ierr = MatSetValues(A,1,&j,1,&i,&v,INSERT_VALUES);CHKERRQ(ierr); } i=0; j=3; v=2; ierr = MatSetValues(A,1,&i,1,&j,&v,INSERT_VALUES);CHKERRQ(ierr); ierr = MatSetValues(A,1,&j,1,&i,&v,INSERT_VALUES);CHKERRQ(ierr); ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); ierr = VecAssemblyBegin(B);CHKERRQ(ierr); ierr = VecAssemblyEnd(B);CHKERRQ(ierr); printf("\nThe Kershaw matrix:\n\n"); MatView(A,0); /* * A Conjugate Gradient method * with ILU(0) preconditioning */ ierr = KSPCreate(comm,&ksp);CHKERRQ(ierr); ierr = KSPSetOperators(ksp,A,A,DIFFERENT_NONZERO_PATTERN);CHKERRQ(ierr); ierr = KSPSetType(ksp,KSPCG);CHKERRQ(ierr); ierr = KSPSetInitialGuessNonzero(ksp,PETSC_TRUE);CHKERRQ(ierr); /* * ILU preconditioner; * The iterative method will break down unless you comment in the SetShift * line below, or use the -pc_factor_shift_positive_definite option. * Run the code twice: once as given to see the negative pivot and the * divergence behaviour, then comment in the Shift line, or add the * command line option, and see that the pivots are all positive and * the method converges. */ ierr = KSPGetPC(ksp,&pc);CHKERRQ(ierr); ierr = PCSetType(pc,PCICC);CHKERRQ(ierr); /* ierr = PCFactorSetShiftType(prec,MAT_SHIFT_POSITIVE_DEFINITE);CHKERRQ(ierr); */ ierr = KSPSetFromOptions(ksp);CHKERRQ(ierr); ierr = KSPSetUp(ksp);CHKERRQ(ierr); /* * Now that the factorisation is done, show the pivots; * note that the last one is negative. This in itself is not an error, * but it will make the iterative method diverge. */ ierr = PCFactorGetMatrix(pc,&M);CHKERRQ(ierr); ierr = VecDuplicate(B,&D);CHKERRQ(ierr); ierr = MatGetDiagonal(M,D);CHKERRQ(ierr); printf("\nPivots:\n\n"); VecView(D,0); /* * Solve the system; * without the shift this will diverge with * an indefinite preconditioner */ ierr = KSPSolve(ksp,B,X);CHKERRQ(ierr); ierr = KSPGetConvergedReason(ksp,&reason);CHKERRQ(ierr); if (reason==KSP_DIVERGED_INDEFINITE_PC) { printf("\nDivergence because of indefinite preconditioner;\n"); printf("Run the executable again but with -pc_factor_shift_positive_definite option.\n"); } else if (reason<0) { printf("\nOther kind of divergence: this should not happen.\n"); } else { ierr = KSPGetIterationNumber(ksp,&its);CHKERRQ(ierr); printf("\nConvergence in %d iterations.\n",(int)its); } printf("\n"); ierr = KSPDestroy(&ksp);CHKERRQ(ierr); ierr = MatDestroy(&A);CHKERRQ(ierr); ierr = VecDestroy(&B);CHKERRQ(ierr); ierr = VecDestroy(&X);CHKERRQ(ierr); ierr = VecDestroy(&D);CHKERRQ(ierr); PetscFinalize(); PetscFunctionReturn(0); }
PetscInt main(PetscInt argc,char **args) { Mat A,As; PetscBool flg,disp_mat=PETSC_FALSE; PetscErrorCode ierr; PetscMPIInt size,rank; PetscInt i,j; PetscScalar v,sigma2; PetscRandom rctx; PetscReal h2,sigma1=100.0; PetscInt dim,Ii,J,n = 3,use_random,rstart,rend; KSP ksp; PC pc; Mat F; PetscInt nneg, nzero, npos; PetscInitialize(&argc,&args,(char *)0,help); #if !defined(PETSC_USE_COMPLEX) SETERRQ(PETSC_COMM_WORLD,1,"This example requires complex numbers"); #endif ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr); ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr); ierr = PetscOptionsHasName(PETSC_NULL, "-display_mat", &disp_mat);CHKERRQ(ierr); ierr = PetscOptionsGetReal(PETSC_NULL,"-sigma1",&sigma1,PETSC_NULL);CHKERRQ(ierr); ierr = PetscOptionsGetInt(PETSC_NULL,"-n",&n,PETSC_NULL);CHKERRQ(ierr); dim = n*n; ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr); ierr = MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,dim,dim);CHKERRQ(ierr); ierr = MatSetType(A,MATAIJ);CHKERRQ(ierr); ierr = MatSetFromOptions(A);CHKERRQ(ierr); ierr = PetscOptionsHasName(PETSC_NULL,"-norandom",&flg);CHKERRQ(ierr); if (flg) use_random = 0; else use_random = 1; if (use_random) { ierr = PetscRandomCreate(PETSC_COMM_WORLD,&rctx);CHKERRQ(ierr); ierr = PetscRandomSetFromOptions(rctx);CHKERRQ(ierr); ierr = PetscRandomSetInterval(rctx,0.0,PETSC_i);CHKERRQ(ierr); ierr = PetscRandomGetValue(rctx,&sigma2);CHKERRQ(ierr); /* RealPart(sigma2) == 0.0 */ } else { sigma2 = 10.0*PETSC_i; } h2 = 1.0/((n+1)*(n+1)); ierr = MatGetOwnershipRange(A,&rstart,&rend);CHKERRQ(ierr); for (Ii=rstart; Ii<rend; Ii++) { v = -1.0; i = Ii/n; j = Ii - i*n; if (i>0) { J = Ii-n; ierr = MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);CHKERRQ(ierr);} if (i<n-1) { J = Ii+n; ierr = MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);CHKERRQ(ierr);} if (j>0) { J = Ii-1; ierr = MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);CHKERRQ(ierr);} if (j<n-1) { J = Ii+1; ierr = MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);CHKERRQ(ierr);} v = 4.0 - sigma1*h2; ierr = MatSetValues(A,1,&Ii,1,&Ii,&v,ADD_VALUES);CHKERRQ(ierr); } ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); /* Check whether A is symmetric */ ierr = PetscOptionsHasName(PETSC_NULL, "-check_symmetric", &flg);CHKERRQ(ierr); if (flg) { Mat Trans; ierr = MatTranspose(A,MAT_INITIAL_MATRIX, &Trans); ierr = MatEqual(A, Trans, &flg); if (!flg) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_USER,"A is not symmetric"); ierr = MatDestroy(&Trans);CHKERRQ(ierr); } ierr = MatSetOption(A,MAT_SYMMETRIC,PETSC_TRUE);CHKERRQ(ierr); /* make A complex Hermitian */ Ii = 0; J = dim-1; if (Ii >= rstart && Ii < rend){ v = sigma2*h2; /* RealPart(v) = 0.0 */ ierr = MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);CHKERRQ(ierr); v = -sigma2*h2; ierr = MatSetValues(A,1,&J,1,&Ii,&v,ADD_VALUES);CHKERRQ(ierr); } Ii = dim-2; J = dim-1; if (Ii >= rstart && Ii < rend){ v = sigma2*h2; /* RealPart(v) = 0.0 */ ierr = MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);CHKERRQ(ierr); v = -sigma2*h2; ierr = MatSetValues(A,1,&J,1,&Ii,&v,ADD_VALUES);CHKERRQ(ierr); } ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); /* Check whether A is Hermitian */ ierr = PetscOptionsHasName(PETSC_NULL, "-check_Hermitian", &flg);CHKERRQ(ierr); if (flg) { Mat Hermit; if (disp_mat){ if (!rank) printf(" A:\n"); ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); } ierr = MatHermitianTranspose(A,MAT_INITIAL_MATRIX, &Hermit); if (disp_mat){ if (!rank) printf(" A_Hermitian:\n"); ierr = MatView(Hermit,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); } ierr = MatEqual(A, Hermit, &flg); if (!flg) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_USER,"A is not Hermitian"); ierr = MatDestroy(&Hermit);CHKERRQ(ierr); } ierr = MatSetOption(A,MAT_HERMITIAN,PETSC_TRUE);CHKERRQ(ierr); /* Create a Hermitian matrix As in sbaij format */ ierr = MatConvert(A,MATSBAIJ,MAT_INITIAL_MATRIX,&As);CHKERRQ(ierr); if (disp_mat){ if (!rank) {ierr = PetscPrintf(PETSC_COMM_SELF," As:\n");CHKERRQ(ierr);} ierr = MatView(As,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); } /* Test MatGetInertia() */ ierr = KSPCreate(PETSC_COMM_WORLD,&ksp);CHKERRQ(ierr); ierr = KSPSetType(ksp,KSPPREONLY);CHKERRQ(ierr); ierr = KSPSetOperators(ksp,As,As,DIFFERENT_NONZERO_PATTERN);CHKERRQ(ierr); ierr = KSPGetPC(ksp,&pc);CHKERRQ(ierr); ierr = PCSetType(pc,PCCHOLESKY);CHKERRQ(ierr); ierr = PCSetFromOptions(pc);CHKERRQ(ierr); ierr = PCSetUp(pc);CHKERRQ(ierr); ierr = PCFactorGetMatrix(pc,&F);CHKERRQ(ierr); ierr = MatGetInertia(F,&nneg,&nzero,&npos);CHKERRQ(ierr); ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr); if (!rank){ ierr = PetscPrintf(PETSC_COMM_SELF," MatInertia: nneg: %D, nzero: %D, npos: %D\n",nneg,nzero,npos);CHKERRQ(ierr); } /* Free spaces */ ierr = KSPDestroy(&ksp);CHKERRQ(ierr); if (use_random) {ierr = PetscRandomDestroy(&rctx);CHKERRQ(ierr);} ierr = MatDestroy(&A);CHKERRQ(ierr); ierr = MatDestroy(&As);CHKERRQ(ierr); ierr = PetscFinalize(); return 0; }
int main(int argc,char **args) { Mat A,B,F; PetscErrorCode ierr; KSP ksp; PC pc; PetscInt N, n=10, m, Istart, Iend, II, J, i,j; PetscInt nneg, nzero, npos; PetscScalar v,sigma; PetscBool flag,loadA=PETSC_FALSE,loadB=PETSC_FALSE; char file[2][PETSC_MAX_PATH_LEN]; PetscViewer viewer; PetscMPIInt rank; PetscInitialize(&argc,&args,(char *)0,help); /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Compute the matrices that define the eigensystem, Ax=kBx - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ ierr = PetscOptionsGetString(PETSC_NULL,"-fA",file[0],PETSC_MAX_PATH_LEN,&loadA);CHKERRQ(ierr); if (loadA) { ierr = PetscViewerBinaryOpen(PETSC_COMM_WORLD,file[0],FILE_MODE_READ,&viewer);CHKERRQ(ierr); ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr); ierr = MatSetType(A,MATSBAIJ);CHKERRQ(ierr); ierr = MatLoad(A,viewer);CHKERRQ(ierr); ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr); ierr = PetscOptionsGetString(PETSC_NULL,"-fB",file[1],PETSC_MAX_PATH_LEN,&loadB);CHKERRQ(ierr); if (loadB){ /* load B to get A = A + sigma*B */ ierr = PetscViewerBinaryOpen(PETSC_COMM_WORLD,file[1],FILE_MODE_READ,&viewer);CHKERRQ(ierr); ierr = MatCreate(PETSC_COMM_WORLD,&B);CHKERRQ(ierr); ierr = MatSetType(B,MATSBAIJ);CHKERRQ(ierr); ierr = MatLoad(B,viewer);CHKERRQ(ierr); ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr); } } if (!loadA) { /* Matrix A is copied from slepc-3.0.0-p6/src/examples/ex13.c. */ ierr = PetscOptionsGetInt(PETSC_NULL,"-n",&n,PETSC_NULL);CHKERRQ(ierr); ierr = PetscOptionsGetInt(PETSC_NULL,"-m",&m,&flag);CHKERRQ(ierr); if( flag==PETSC_FALSE ) m=n; N = n*m; ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr); ierr = MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,N,N);CHKERRQ(ierr); ierr = MatSetType(A,MATSBAIJ);CHKERRQ(ierr); ierr = MatSetFromOptions(A);CHKERRQ(ierr); ierr = MatSetUp(A);CHKERRQ(ierr); ierr = MatSetOption(A,MAT_IGNORE_LOWER_TRIANGULAR,PETSC_TRUE);CHKERRQ(ierr); ierr = MatGetOwnershipRange(A,&Istart,&Iend);CHKERRQ(ierr); for( II=Istart; II<Iend; II++ ) { v = -1.0; i = II/n; j = II-i*n; if(i>0) { J=II-n; MatSetValues(A,1,&II,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr); } if(i<m-1) { J=II+n; MatSetValues(A,1,&II,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr); } if(j>0) { J=II-1; MatSetValues(A,1,&II,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr); } if(j<n-1) { J=II+1; MatSetValues(A,1,&II,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr); } v=4.0; MatSetValues(A,1,&II,1,&II,&v,INSERT_VALUES);CHKERRQ(ierr); } ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); } /* ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); */ if (!loadB) { ierr = MatGetLocalSize(A,&m,&n);CHKERRQ(ierr); ierr = MatCreate(PETSC_COMM_WORLD,&B);CHKERRQ(ierr); ierr = MatSetSizes(B,m,n,PETSC_DECIDE,PETSC_DECIDE);CHKERRQ(ierr); ierr = MatSetType(B,MATSBAIJ);CHKERRQ(ierr); ierr = MatSetFromOptions(B);CHKERRQ(ierr); ierr = MatSetUp(B);CHKERRQ(ierr); ierr = MatSetOption(B,MAT_IGNORE_LOWER_TRIANGULAR,PETSC_TRUE);CHKERRQ(ierr); ierr = MatGetOwnershipRange(A,&Istart,&Iend);CHKERRQ(ierr); for( II=Istart; II<Iend; II++ ) { /* v=4.0; MatSetValues(B,1,&II,1,&II,&v,INSERT_VALUES);CHKERRQ(ierr); */ v=1.0; MatSetValues(B,1,&II,1,&II,&v,INSERT_VALUES);CHKERRQ(ierr); } ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); } /* ierr = MatView(B,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); */ /* Set a shift: A = A - sigma*B */ ierr = PetscOptionsGetScalar(PETSC_NULL,"-sigma",&sigma,&flag);CHKERRQ(ierr); if (flag){ sigma = -1.0 * sigma; ierr = MatAXPY(A,sigma,B,DIFFERENT_NONZERO_PATTERN);CHKERRQ(ierr); /* A <- A - sigma*B */ /* ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); */ } /* Test MatGetInertia() */ ierr = KSPCreate(PETSC_COMM_WORLD,&ksp);CHKERRQ(ierr); ierr = KSPSetType(ksp,KSPPREONLY);CHKERRQ(ierr); ierr = KSPSetOperators(ksp,A,A,DIFFERENT_NONZERO_PATTERN);CHKERRQ(ierr); ierr = KSPGetPC(ksp,&pc);CHKERRQ(ierr); ierr = PCSetType(pc,PCCHOLESKY);CHKERRQ(ierr); ierr = PCSetFromOptions(pc);CHKERRQ(ierr); ierr = PCSetUp(pc);CHKERRQ(ierr); ierr = PCFactorGetMatrix(pc,&F);CHKERRQ(ierr); ierr = MatGetInertia(F,&nneg,&nzero,&npos);CHKERRQ(ierr); ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr); if (!rank){ ierr = PetscPrintf(PETSC_COMM_SELF," MatInertia: nneg: %D, nzero: %D, npos: %D\n",nneg,nzero,npos);CHKERRQ(ierr); } /* Destroy */ ierr = KSPDestroy(&ksp);CHKERRQ(ierr); ierr = MatDestroy(&A);CHKERRQ(ierr); ierr = MatDestroy(&B);CHKERRQ(ierr); ierr = PetscFinalize(); return 0; }
// ===================================================== void PetscPreconditioner::set_petsc_preconditioner_type (const PreconditionerType & preconditioner_type, PC & pc, const int ¶llelOverlapping) { int ierr = 0; switch(preconditioner_type) { case IDENTITY_PRECOND: ierr = PCSetType(pc, (char*) PCNONE); CHKERRABORT(MPI_COMM_WORLD, ierr); break; case CHOLESKY_PRECOND: ierr = PCSetType(pc, (char*) PCCHOLESKY); CHKERRABORT(MPI_COMM_WORLD, ierr); break; case ICC_PRECOND: ierr = PCSetType(pc, (char*) PCICC); CHKERRABORT(MPI_COMM_WORLD, ierr); break; case ILU_PRECOND: { int nprocs; MPI_Comm_size(MPI_COMM_WORLD, &nprocs); //TODO // In serial, just set the ILU preconditioner type if(nprocs == 1) { ierr = PCSetType(pc, (char*) PCILU); CHKERRABORT(MPI_COMM_WORLD, ierr); } else { // But PETSc has no truly parallel ILU, instead you have to set // an actual parallel preconditioner (e.g. block Jacobi (parlleloverlapping 0) or ASM (parlleloverlapping >0)) // and then assign ILU sub-preconditioners. set_petsc_preconditioner_type(ASM_PRECOND, pc); PCASMSetOverlap(pc, parallelOverlapping); PCSetUp(pc); // Set ILU as the sub preconditioner type set_petsc_subpreconditioner_type(PCILU, pc); } break; } case LU_PRECOND: { int nprocs; MPI_Comm_size(MPI_COMM_WORLD, &nprocs); if(nprocs == 1) { ierr = PCSetType(pc, (char*) PCLU); CHKERRABORT(MPI_COMM_WORLD, ierr); } else { ierr = PCSetType(pc, (char*) PCLU); CHKERRABORT(MPI_COMM_WORLD, ierr); ierr = PCFactorSetMatSolverPackage(pc, MATSOLVERMUMPS); CHKERRABORT(MPI_COMM_WORLD, ierr); ierr = PCFactorSetUpMatSolverPackage(pc); CHKERRABORT(MPI_COMM_WORLD, ierr); Mat F; ierr = PCFactorGetMatrix(pc, &F); CHKERRABORT(MPI_COMM_WORLD, ierr); ierr = MatMumpsSetIcntl(F, 14, 30); CHKERRABORT(MPI_COMM_WORLD, ierr); } break; } case SLU_PRECOND: ierr = PCSetType(pc, (char*) PCLU); CHKERRABORT(MPI_COMM_WORLD, ierr); ierr = PCFactorSetMatSolverPackage(pc, MATSOLVERSUPERLU_DIST); CHKERRABORT(MPI_COMM_WORLD, ierr); break; //here we set the SuperLU_dist solver package case MLU_PRECOND: //here we set the MUMPS parallel direct solver package ierr = PCSetType(pc, (char*) PCLU); CHKERRABORT(MPI_COMM_WORLD, ierr); ierr = PCFactorSetMatSolverPackage(pc, MATSOLVERMUMPS); CHKERRABORT(MPI_COMM_WORLD, ierr); ierr = PCFactorSetUpMatSolverPackage(pc); CHKERRABORT(MPI_COMM_WORLD, ierr); Mat F; ierr = PCFactorGetMatrix(pc, &F); CHKERRABORT(MPI_COMM_WORLD, ierr); ierr = MatMumpsSetIcntl(F, 14, 30); CHKERRABORT(MPI_COMM_WORLD, ierr); break; case ULU_PRECOND: //here we set the Umfpack serial direct solver package ierr = PCSetType(pc, (char*) PCLU); CHKERRABORT(MPI_COMM_WORLD, ierr); ierr = PCFactorSetMatSolverPackage(pc, MATSOLVERUMFPACK); CHKERRABORT(MPI_COMM_WORLD, ierr); ierr = PCFactorSetUpMatSolverPackage(pc); CHKERRABORT(MPI_COMM_WORLD, ierr); break; case MCC_PRECOND: ierr = PCSetType(pc, (char*) PCCHOLESKY); CHKERRABORT(MPI_COMM_WORLD, ierr); ierr = PCFactorSetMatSolverPackage(pc, MATSOLVERMUMPS); CHKERRABORT(MPI_COMM_WORLD, ierr); //here we set the MUMPS parallel direct solver package break; case ASM_PRECOND: ierr = PCSetType(pc, (char*) PCASM); CHKERRABORT(MPI_COMM_WORLD, ierr); break; case FIELDSPLIT_PRECOND: ierr = PCSetType(pc, (char*) PCFIELDSPLIT); CHKERRABORT(MPI_COMM_WORLD, ierr); break; case JACOBI_PRECOND: ierr = PCSetType(pc, (char*) PCJACOBI); CHKERRABORT(MPI_COMM_WORLD, ierr); break; case BLOCK_JACOBI_PRECOND: ierr = PCSetType(pc, (char*) PCBJACOBI); CHKERRABORT(MPI_COMM_WORLD, ierr); break; case SOR_PRECOND: ierr = PCSetType(pc, (char*) PCSOR); CHKERRABORT(MPI_COMM_WORLD, ierr); break; case EISENSTAT_PRECOND: ierr = PCSetType(pc, (char*) PCEISENSTAT); CHKERRABORT(MPI_COMM_WORLD, ierr); break; case AMG_PRECOND: ierr = PCSetType(pc, (char*) PCHYPRE); CHKERRABORT(MPI_COMM_WORLD, ierr); break; case MG_PRECOND: ierr = PCSetType(pc, (char*) PCMG); CHKERRABORT(MPI_COMM_WORLD, ierr); break; case LSC_PRECOND: ierr = PCSetType(pc, (char*) PCLSC); CHKERRABORT(MPI_COMM_WORLD, ierr); break; #if !(PETSC_VERSION_LESS_THAN(2,1,2)) // Only available for PETSC >= 2.1.2 case USER_PRECOND: ierr = PCSetType(pc, (char*) PCMAT); CHKERRABORT(MPI_COMM_WORLD, ierr); break; #endif case SHELL_PRECOND: ierr = PCSetType(pc, (char*) PCSHELL); CHKERRABORT(MPI_COMM_WORLD, ierr); break; default: std::cerr << "ERROR: Unsupported PETSC Preconditioner: " << preconditioner_type << std::endl << "Continuing with PETSC defaults" << std::endl; } //Let the commandline override stuff if(preconditioner_type != AMG_PRECOND && preconditioner_type != MG_PRECOND) PCSetFromOptions(pc); //!!!!!! }
int main(int argc,char **argv) { KSP solver; PC prec; Mat A,M; Vec X,B,D; MPI_Comm comm; PetscScalar v; KSPConvergedReason reason; PetscInt i,j,its; PetscErrorCode ierr; ierr = PetscInitialize(&argc,&argv,0,help);CHKERRQ(ierr); comm = MPI_COMM_SELF; /* * Construct the Kershaw matrix * and a suitable rhs / initial guess */ ierr = MatCreateSeqAIJ(comm,4,4,4,0,&A);CHKERRQ(ierr); ierr = VecCreateSeq(comm,4,&B);CHKERRQ(ierr); ierr = VecDuplicate(B,&X);CHKERRQ(ierr); for (i=0; i<4; i++) { v = 3; ierr = MatSetValues(A,1,&i,1,&i,&v,INSERT_VALUES);CHKERRQ(ierr); v = 1; ierr = VecSetValues(B,1,&i,&v,INSERT_VALUES);CHKERRQ(ierr); ierr = VecSetValues(X,1,&i,&v,INSERT_VALUES);CHKERRQ(ierr); } i=0; v=0; ierr = VecSetValues(X,1,&i,&v,INSERT_VALUES);CHKERRQ(ierr); for (i=0; i<3; i++) { v = -2; j=i+1; ierr = MatSetValues(A,1,&i,1,&j,&v,INSERT_VALUES);CHKERRQ(ierr); ierr = MatSetValues(A,1,&j,1,&i,&v,INSERT_VALUES);CHKERRQ(ierr); } i=0; j=3; v=2; ierr = MatSetValues(A,1,&i,1,&j,&v,INSERT_VALUES);CHKERRQ(ierr); ierr = MatSetValues(A,1,&j,1,&i,&v,INSERT_VALUES);CHKERRQ(ierr); ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); ierr = VecAssemblyBegin(B);CHKERRQ(ierr); ierr = VecAssemblyEnd(B);CHKERRQ(ierr); /* * A Conjugate Gradient method * with ILU(0) preconditioning */ ierr = KSPCreate(comm,&solver);CHKERRQ(ierr); ierr = KSPSetOperators(solver,A,A);CHKERRQ(ierr); ierr = KSPSetType(solver,KSPCG);CHKERRQ(ierr); ierr = KSPSetInitialGuessNonzero(solver,PETSC_TRUE);CHKERRQ(ierr); /* * ILU preconditioner; * this will break down unless you add the Shift line, * or use the -pc_factor_shift_positive_definite option */ ierr = KSPGetPC(solver,&prec);CHKERRQ(ierr); ierr = PCSetType(prec,PCILU);CHKERRQ(ierr); /* ierr = PCFactorSetShiftType(prec,MAT_SHIFT_POSITIVE_DEFINITE);CHKERRQ(ierr); */ ierr = KSPSetFromOptions(solver);CHKERRQ(ierr); ierr = KSPSetUp(solver);CHKERRQ(ierr); /* * Now that the factorisation is done, show the pivots; * note that the last one is negative. This in itself is not an error, * but it will make the iterative method diverge. */ ierr = PCFactorGetMatrix(prec,&M);CHKERRQ(ierr); ierr = VecDuplicate(B,&D);CHKERRQ(ierr); ierr = MatGetDiagonal(M,D);CHKERRQ(ierr); /* * Solve the system; * without the shift this will diverge with * an indefinite preconditioner */ ierr = KSPSolve(solver,B,X);CHKERRQ(ierr); ierr = KSPGetConvergedReason(solver,&reason);CHKERRQ(ierr); if (reason==KSP_DIVERGED_INDEFINITE_PC) { ierr = PetscPrintf(PETSC_COMM_WORLD,"\nDivergence because of indefinite preconditioner;\n");CHKERRQ(ierr); ierr = PetscPrintf(PETSC_COMM_WORLD,"Run the executable again but with '-pc_factor_shift_type POSITIVE_DEFINITE' option.\n");CHKERRQ(ierr); } else if (reason<0) { ierr = PetscPrintf(PETSC_COMM_WORLD,"\nOther kind of divergence: this should not happen.\n");CHKERRQ(ierr); } else { ierr = KSPGetIterationNumber(solver,&its);CHKERRQ(ierr); } ierr = VecDestroy(&X);CHKERRQ(ierr); ierr = VecDestroy(&B);CHKERRQ(ierr); ierr = VecDestroy(&D);CHKERRQ(ierr); ierr = MatDestroy(&A);CHKERRQ(ierr); ierr = KSPDestroy(&solver);CHKERRQ(ierr); PetscFinalize(); return 0; }
/*@ MatSchurComplementComputeExplicitOperator - Compute the Schur complement matrix explicitly Collective on Mat Input Parameter: . M - the matrix obtained with MatCreateSchurComplement() Output Parameter: . S - the Schur complement matrix Note: This can be expensive, so it is mainly for testing Level: advanced .seealso: MatCreateSchurComplement(), MatSchurComplementUpdate() @*/ PetscErrorCode MatSchurComplementComputeExplicitOperator(Mat M, Mat *S) { Mat B, C, D; KSP ksp; PC pc; PetscBool isLU, isILU; PetscReal fill = 2.0; PetscErrorCode ierr; PetscFunctionBegin; ierr = MatSchurComplementGetSubMatrices(M, NULL, NULL, &B, &C, &D);CHKERRQ(ierr); ierr = MatSchurComplementGetKSP(M, &ksp);CHKERRQ(ierr); ierr = KSPGetPC(ksp, &pc);CHKERRQ(ierr); ierr = PetscObjectTypeCompare((PetscObject) pc, PCLU, &isLU);CHKERRQ(ierr); ierr = PetscObjectTypeCompare((PetscObject) pc, PCILU, &isILU);CHKERRQ(ierr); if (isLU || isILU) { Mat fact, Bd, AinvB, AinvBd; PetscReal eps = 1.0e-10; /* This can be sped up for banded LU */ ierr = KSPSetUp(ksp);CHKERRQ(ierr); ierr = PCFactorGetMatrix(pc, &fact);CHKERRQ(ierr); ierr = MatConvert(B, MATDENSE, MAT_INITIAL_MATRIX, &Bd);CHKERRQ(ierr); ierr = MatDuplicate(Bd, MAT_DO_NOT_COPY_VALUES, &AinvBd);CHKERRQ(ierr); ierr = MatMatSolve(fact, Bd, AinvBd);CHKERRQ(ierr); ierr = MatDestroy(&Bd);CHKERRQ(ierr); ierr = MatChop(AinvBd, eps);CHKERRQ(ierr); ierr = MatConvert(AinvBd, MATAIJ, MAT_INITIAL_MATRIX, &AinvB);CHKERRQ(ierr); ierr = MatDestroy(&AinvBd);CHKERRQ(ierr); ierr = MatMatMult(C, AinvB, MAT_INITIAL_MATRIX, fill, S);CHKERRQ(ierr); ierr = MatDestroy(&AinvB);CHKERRQ(ierr); } else { Mat Ainvd, Ainv; ierr = PCComputeExplicitOperator(pc, &Ainvd);CHKERRQ(ierr); ierr = MatConvert(Ainvd, MATAIJ, MAT_INITIAL_MATRIX, &Ainv);CHKERRQ(ierr); ierr = MatDestroy(&Ainvd);CHKERRQ(ierr); #if 0 /* Symmetric version */ ierr = MatPtAP(Ainv, B, MAT_INITIAL_MATRIX, fill, S);CHKERRQ(ierr); #else /* Nonsymmetric version */ ierr = MatMatMatMult(C, Ainv, B, MAT_INITIAL_MATRIX, fill, S);CHKERRQ(ierr); #endif ierr = MatDestroy(&Ainv);CHKERRQ(ierr); } ierr = PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD, PETSC_VIEWER_ASCII_INFO);CHKERRQ(ierr); ierr = MatView(*S, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); ierr = PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); if (D) { MatInfo info; PetscReal norm; ierr = MatGetInfo(D, MAT_GLOBAL_SUM, &info);CHKERRQ(ierr); if (info.nz_used) { ierr = MatNorm(D, NORM_INFINITY, &norm);CHKERRQ(ierr); if (norm > PETSC_MACHINE_EPSILON) SETERRQ(PetscObjectComm((PetscObject) M), PETSC_ERR_SUP, "Not yet implemented for Schur complements with non-vanishing D"); } } PetscFunctionReturn(0); }
PETSC_EXTERN void PETSC_STDCALL pcfactorgetmatrix_(PC pc,Mat *mat, int *__ierr ){ *__ierr = PCFactorGetMatrix( (PC)PetscToPointer((pc) ),mat); }