1 #include <../src/ksp/pc/impls/bddc/bddc.h> 2 #include <../src/ksp/pc/impls/bddc/bddcprivate.h> 3 4 static PetscErrorCode PCBDDCApplyNullSpaceCorrectionPC(PC pc,Vec x,Vec y) 5 { 6 NullSpaceCorrection_ctx pc_ctx; 7 PetscErrorCode ierr; 8 9 PetscFunctionBegin; 10 ierr = PCShellGetContext(pc,(void**)&pc_ctx);CHKERRQ(ierr); 11 /* E */ 12 ierr = MatMultTranspose(pc_ctx->Lbasis_mat,x,pc_ctx->work_small_2);CHKERRQ(ierr); 13 ierr = MatMultAdd(pc_ctx->Kbasis_mat,pc_ctx->work_small_2,x,pc_ctx->work_full_1);CHKERRQ(ierr); 14 /* P^-1 */ 15 ierr = PCApply(pc_ctx->local_pc,pc_ctx->work_full_1,pc_ctx->work_full_2);CHKERRQ(ierr); 16 /* E^T */ 17 ierr = MatMultTranspose(pc_ctx->Kbasis_mat,pc_ctx->work_full_2,pc_ctx->work_small_1);CHKERRQ(ierr); 18 ierr = VecScale(pc_ctx->work_small_1,-1.0);CHKERRQ(ierr); 19 ierr = MatMultAdd(pc_ctx->Lbasis_mat,pc_ctx->work_small_1,pc_ctx->work_full_2,pc_ctx->work_full_1);CHKERRQ(ierr); 20 /* Sum contributions */ 21 ierr = MatMultAdd(pc_ctx->basis_mat,pc_ctx->work_small_2,pc_ctx->work_full_1,y);CHKERRQ(ierr); 22 if (pc_ctx->apply_scaling) { 23 ierr = VecScale(y,pc_ctx->scale);CHKERRQ(ierr); 24 } 25 PetscFunctionReturn(0); 26 } 27 28 static PetscErrorCode PCBDDCDestroyNullSpaceCorrectionPC(PC pc) 29 { 30 NullSpaceCorrection_ctx pc_ctx; 31 PetscErrorCode ierr; 32 33 PetscFunctionBegin; 34 ierr = PCShellGetContext(pc,(void**)&pc_ctx);CHKERRQ(ierr); 35 ierr = VecDestroy(&pc_ctx->work_small_1);CHKERRQ(ierr); 36 ierr = VecDestroy(&pc_ctx->work_small_2);CHKERRQ(ierr); 37 ierr = VecDestroy(&pc_ctx->work_full_1);CHKERRQ(ierr); 38 ierr = VecDestroy(&pc_ctx->work_full_2);CHKERRQ(ierr); 39 ierr = MatDestroy(&pc_ctx->basis_mat);CHKERRQ(ierr); 40 ierr = MatDestroy(&pc_ctx->Lbasis_mat);CHKERRQ(ierr); 41 ierr = MatDestroy(&pc_ctx->Kbasis_mat);CHKERRQ(ierr); 42 ierr = PCDestroy(&pc_ctx->local_pc);CHKERRQ(ierr); 43 ierr = PetscFree(pc_ctx);CHKERRQ(ierr); 44 PetscFunctionReturn(0); 45 } 46 47 PetscErrorCode PCBDDCNullSpaceAssembleCorrection(PC pc, PetscBool isdir, PetscBool needscaling) 48 { 49 PC_BDDC *pcbddc = (PC_BDDC*)pc->data; 50 PC_IS *pcis = (PC_IS*)pc->data; 51 Mat_IS *matis = (Mat_IS*)pc->pmat->data; 52 MatNullSpace NullSpace = NULL; 53 KSP local_ksp; 54 PC newpc; 55 NullSpaceCorrection_ctx shell_ctx; 56 Mat local_mat,local_pmat,small_mat,inv_small_mat; 57 const Vec *nullvecs; 58 VecScatter scatter_ctx; 59 IS is_aux,local_dofs; 60 MatFactorInfo matinfo; 61 PetscScalar *basis_mat,*Kbasis_mat,*array,*array_mat; 62 PetscScalar one = 1.0,zero = 0.0, m_one = -1.0; 63 PetscInt basis_dofs,basis_size,nnsp_size,i,k; 64 PetscBool nnsp_has_cnst; 65 PetscReal test_err,lambda_min,lambda_max; 66 PetscBool setsym,issym=PETSC_FALSE; 67 PetscErrorCode ierr; 68 69 PetscFunctionBegin; 70 ierr = MatGetNullSpace(matis->A,&NullSpace);CHKERRQ(ierr); 71 if (!NullSpace) PetscFunctionReturn(0); 72 /* Infer the local solver */ 73 if (isdir) { 74 /* Dirichlet solver */ 75 local_ksp = pcbddc->ksp_D; 76 local_dofs = pcis->is_I_local; 77 } else { 78 /* Neumann solver */ 79 local_ksp = pcbddc->ksp_R; 80 local_dofs = pcbddc->is_R_local; 81 } 82 ierr = ISGetSize(local_dofs,&basis_dofs);CHKERRQ(ierr); 83 ierr = KSPGetOperators(local_ksp,&local_mat,&local_pmat);CHKERRQ(ierr); 84 85 /* Get null space vecs */ 86 ierr = MatNullSpaceGetVecs(NullSpace,&nnsp_has_cnst,&nnsp_size,&nullvecs);CHKERRQ(ierr); 87 basis_size = nnsp_size; 88 if (nnsp_has_cnst) basis_size++; 89 90 /* Create shell ctx */ 91 ierr = PetscNew(&shell_ctx);CHKERRQ(ierr); 92 shell_ctx->apply_scaling = needscaling; 93 94 /* Create work vectors in shell context */ 95 ierr = VecCreate(PETSC_COMM_SELF,&shell_ctx->work_small_1);CHKERRQ(ierr); 96 ierr = VecSetSizes(shell_ctx->work_small_1,basis_size,basis_size);CHKERRQ(ierr); 97 ierr = VecSetType(shell_ctx->work_small_1,VECSEQ);CHKERRQ(ierr); 98 ierr = VecDuplicate(shell_ctx->work_small_1,&shell_ctx->work_small_2);CHKERRQ(ierr); 99 ierr = VecCreate(PETSC_COMM_SELF,&shell_ctx->work_full_1);CHKERRQ(ierr); 100 ierr = VecSetSizes(shell_ctx->work_full_1,basis_dofs,basis_dofs);CHKERRQ(ierr); 101 ierr = VecSetType(shell_ctx->work_full_1,VECSEQ);CHKERRQ(ierr); 102 ierr = VecDuplicate(shell_ctx->work_full_1,&shell_ctx->work_full_2);CHKERRQ(ierr); 103 104 /* Allocate workspace */ 105 ierr = MatCreateSeqDense(PETSC_COMM_SELF,basis_dofs,basis_size,NULL,&shell_ctx->basis_mat);CHKERRQ(ierr); 106 ierr = MatCreateSeqDense(PETSC_COMM_SELF,basis_dofs,basis_size,NULL,&shell_ctx->Kbasis_mat);CHKERRQ(ierr); 107 ierr = MatDenseGetArray(shell_ctx->basis_mat,&basis_mat);CHKERRQ(ierr); 108 ierr = MatDenseGetArray(shell_ctx->Kbasis_mat,&Kbasis_mat);CHKERRQ(ierr); 109 110 /* Restrict local null space on selected dofs 111 and compute matrices N and K*N */ 112 ierr = VecScatterCreate(pcis->vec1_N,local_dofs,shell_ctx->work_full_1,(IS)0,&scatter_ctx);CHKERRQ(ierr); 113 for (k=0;k<nnsp_size;k++) { 114 ierr = VecPlaceArray(shell_ctx->work_full_1,(const PetscScalar*)&basis_mat[k*basis_dofs]);CHKERRQ(ierr); 115 ierr = VecScatterBegin(scatter_ctx,nullvecs[k],shell_ctx->work_full_1,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 116 ierr = VecScatterEnd(scatter_ctx,nullvecs[k],shell_ctx->work_full_1,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 117 ierr = VecPlaceArray(shell_ctx->work_full_2,(const PetscScalar*)&Kbasis_mat[k*basis_dofs]);CHKERRQ(ierr); 118 ierr = MatMult(local_mat,shell_ctx->work_full_1,shell_ctx->work_full_2);CHKERRQ(ierr); 119 ierr = VecResetArray(shell_ctx->work_full_1);CHKERRQ(ierr); 120 ierr = VecResetArray(shell_ctx->work_full_2);CHKERRQ(ierr); 121 } 122 if (nnsp_has_cnst) { 123 ierr = VecPlaceArray(shell_ctx->work_full_1,(const PetscScalar*)&basis_mat[k*basis_dofs]);CHKERRQ(ierr); 124 ierr = VecSet(shell_ctx->work_full_1,one);CHKERRQ(ierr); 125 ierr = VecPlaceArray(shell_ctx->work_full_2,(const PetscScalar*)&Kbasis_mat[k*basis_dofs]);CHKERRQ(ierr); 126 ierr = MatMult(local_mat,shell_ctx->work_full_1,shell_ctx->work_full_2);CHKERRQ(ierr); 127 ierr = VecResetArray(shell_ctx->work_full_1);CHKERRQ(ierr); 128 ierr = VecResetArray(shell_ctx->work_full_2);CHKERRQ(ierr); 129 } 130 ierr = VecScatterDestroy(&scatter_ctx);CHKERRQ(ierr); 131 ierr = MatDenseRestoreArray(shell_ctx->basis_mat,&basis_mat);CHKERRQ(ierr); 132 ierr = MatDenseRestoreArray(shell_ctx->Kbasis_mat,&Kbasis_mat);CHKERRQ(ierr); 133 134 /* Assemble another Mat object in shell context */ 135 ierr = MatTransposeMatMult(shell_ctx->basis_mat,shell_ctx->Kbasis_mat,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&small_mat);CHKERRQ(ierr); 136 ierr = MatFactorInfoInitialize(&matinfo);CHKERRQ(ierr); 137 ierr = ISCreateStride(PETSC_COMM_SELF,basis_size,0,1,&is_aux);CHKERRQ(ierr); 138 ierr = MatLUFactor(small_mat,is_aux,is_aux,&matinfo);CHKERRQ(ierr); 139 ierr = ISDestroy(&is_aux);CHKERRQ(ierr); 140 ierr = PetscMalloc1(basis_size*basis_size,&array_mat);CHKERRQ(ierr); 141 for (k=0;k<basis_size;k++) { 142 ierr = VecSet(shell_ctx->work_small_1,zero);CHKERRQ(ierr); 143 ierr = VecSetValue(shell_ctx->work_small_1,k,one,INSERT_VALUES);CHKERRQ(ierr); 144 ierr = VecAssemblyBegin(shell_ctx->work_small_1);CHKERRQ(ierr); 145 ierr = VecAssemblyEnd(shell_ctx->work_small_1);CHKERRQ(ierr); 146 ierr = MatSolve(small_mat,shell_ctx->work_small_1,shell_ctx->work_small_2);CHKERRQ(ierr); 147 ierr = VecGetArrayRead(shell_ctx->work_small_2,(const PetscScalar**)&array);CHKERRQ(ierr); 148 for (i=0;i<basis_size;i++) { 149 array_mat[i*basis_size+k]=array[i]; 150 } 151 ierr = VecRestoreArrayRead(shell_ctx->work_small_2,(const PetscScalar**)&array);CHKERRQ(ierr); 152 } 153 ierr = MatCreateSeqDense(PETSC_COMM_SELF,basis_size,basis_size,array_mat,&inv_small_mat);CHKERRQ(ierr); 154 ierr = MatMatMult(shell_ctx->basis_mat,inv_small_mat,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&shell_ctx->Lbasis_mat);CHKERRQ(ierr); 155 ierr = PetscFree(array_mat);CHKERRQ(ierr); 156 ierr = MatDestroy(&inv_small_mat);CHKERRQ(ierr); 157 ierr = MatDestroy(&small_mat);CHKERRQ(ierr); 158 ierr = MatScale(shell_ctx->Kbasis_mat,m_one);CHKERRQ(ierr); 159 160 /* Rebuild local PC */ 161 ierr = KSPGetPC(local_ksp,&shell_ctx->local_pc);CHKERRQ(ierr); 162 ierr = PetscObjectReference((PetscObject)shell_ctx->local_pc);CHKERRQ(ierr); 163 ierr = PCCreate(PETSC_COMM_SELF,&newpc);CHKERRQ(ierr); 164 ierr = PCSetOperators(newpc,local_mat,local_mat);CHKERRQ(ierr); 165 ierr = PCSetType(newpc,PCSHELL);CHKERRQ(ierr); 166 ierr = PCShellSetContext(newpc,shell_ctx);CHKERRQ(ierr); 167 ierr = PCShellSetApply(newpc,PCBDDCApplyNullSpaceCorrectionPC);CHKERRQ(ierr); 168 ierr = PCShellSetDestroy(newpc,PCBDDCDestroyNullSpaceCorrectionPC);CHKERRQ(ierr); 169 ierr = PCSetUp(newpc);CHKERRQ(ierr); 170 ierr = KSPSetPC(local_ksp,newpc);CHKERRQ(ierr); 171 ierr = KSPSetUp(local_ksp);CHKERRQ(ierr); 172 173 /* Create ksp object suitable for extreme eigenvalues' estimation */ 174 if (needscaling) { 175 KSP check_ksp; 176 Vec *workv; 177 178 ierr = KSPCreate(PETSC_COMM_SELF,&check_ksp);CHKERRQ(ierr); 179 ierr = KSPSetErrorIfNotConverged(check_ksp,pc->erroriffailure);CHKERRQ(ierr); 180 ierr = KSPSetOperators(check_ksp,local_mat,local_mat);CHKERRQ(ierr); 181 ierr = KSPSetTolerances(check_ksp,1.e-4,1.e-12,PETSC_DEFAULT,basis_dofs);CHKERRQ(ierr); 182 ierr = KSPSetComputeSingularValues(check_ksp,PETSC_TRUE);CHKERRQ(ierr); 183 ierr = MatIsSymmetricKnown(pc->pmat,&setsym,&issym);CHKERRQ(ierr); 184 if (issym) { 185 ierr = KSPSetType(check_ksp,KSPCG);CHKERRQ(ierr); 186 } 187 ierr = VecDuplicateVecs(shell_ctx->work_full_1,2,&workv);CHKERRQ(ierr); 188 ierr = KSPSetPC(check_ksp,newpc);CHKERRQ(ierr); 189 ierr = KSPSetUp(check_ksp);CHKERRQ(ierr); 190 ierr = VecSetRandom(workv[1],NULL);CHKERRQ(ierr); 191 ierr = MatMult(local_mat,workv[1],workv[0]);CHKERRQ(ierr); 192 ierr = KSPSolve(check_ksp,workv[0],workv[0]);CHKERRQ(ierr); 193 ierr = VecAXPY(workv[0],-1.,workv[1]);CHKERRQ(ierr); 194 ierr = VecNorm(workv[0],NORM_INFINITY,&test_err);CHKERRQ(ierr); 195 ierr = KSPComputeExtremeSingularValues(check_ksp,&lambda_max,&lambda_min);CHKERRQ(ierr); 196 ierr = KSPGetIterationNumber(check_ksp,&k);CHKERRQ(ierr); 197 if (pcbddc->dbg_flag) { 198 if (isdir) { 199 ierr = PetscViewerASCIISynchronizedPrintf(pcbddc->dbg_viewer,"Subdomain %04d infinity error for Dirichlet adapted solver (no scale) %1.14e (it %d, eigs %1.6e %1.6e)\n",PetscGlobalRank,test_err,k,lambda_min,lambda_max);CHKERRQ(ierr); 200 } else { 201 ierr = PetscViewerASCIISynchronizedPrintf(pcbddc->dbg_viewer,"Subdomain %04d infinity error for Neumann adapted solver (no scale) %1.14e (it %d, eigs %1.6e %1.6e)\n",PetscGlobalRank,test_err,k,lambda_min,lambda_max);CHKERRQ(ierr); 202 } 203 } 204 shell_ctx->scale = 1./lambda_max; 205 ierr = KSPDestroy(&check_ksp);CHKERRQ(ierr); 206 ierr = VecDestroyVecs(2,&workv);CHKERRQ(ierr); 207 } 208 ierr = PCDestroy(&newpc);CHKERRQ(ierr); 209 PetscFunctionReturn(0); 210 } 211 212 PetscErrorCode PCBDDCNullSpaceCheckCorrection(PC pc, PetscBool isdir) 213 { 214 PC_BDDC *pcbddc = (PC_BDDC*)pc->data; 215 Mat_IS *matis = (Mat_IS*)pc->pmat->data; 216 KSP check_ksp,local_ksp; 217 MatNullSpace NullSpace = NULL; 218 NullSpaceCorrection_ctx shell_ctx; 219 PC check_pc; 220 Mat test_mat,local_mat; 221 PetscReal test_err,lambda_min,lambda_max; 222 PetscBool setsym,issym=PETSC_FALSE; 223 Vec work1,work2,work3; 224 PetscInt k; 225 PetscErrorCode ierr; 226 227 PetscFunctionBegin; 228 ierr = MatGetNullSpace(matis->A,&NullSpace);CHKERRQ(ierr); 229 if (!NullSpace) PetscFunctionReturn(0); 230 if (!pcbddc->dbg_flag) PetscFunctionReturn(0); 231 if (isdir) local_ksp = pcbddc->ksp_D; 232 else local_ksp = pcbddc->ksp_R; 233 ierr = KSPGetOperators(local_ksp,&local_mat,NULL);CHKERRQ(ierr); 234 ierr = KSPGetPC(local_ksp,&check_pc);CHKERRQ(ierr); 235 ierr = PCShellGetContext(check_pc,(void**)&shell_ctx);CHKERRQ(ierr); 236 ierr = VecDuplicate(shell_ctx->work_full_1,&work1);CHKERRQ(ierr); 237 ierr = VecDuplicate(shell_ctx->work_full_1,&work2);CHKERRQ(ierr); 238 ierr = VecDuplicate(shell_ctx->work_full_1,&work3);CHKERRQ(ierr); 239 240 ierr = VecSetRandom(shell_ctx->work_small_1,NULL);CHKERRQ(ierr); 241 ierr = MatMult(shell_ctx->basis_mat,shell_ctx->work_small_1,work1);CHKERRQ(ierr); 242 ierr = VecCopy(work1,work2);CHKERRQ(ierr); 243 ierr = MatMult(local_mat,work1,work3);CHKERRQ(ierr); 244 ierr = PCApply(check_pc,work3,work1);CHKERRQ(ierr); 245 ierr = VecAXPY(work1,-1.,work2);CHKERRQ(ierr); 246 ierr = VecNorm(work1,NORM_INFINITY,&test_err);CHKERRQ(ierr); 247 if (isdir) { 248 ierr = PetscViewerASCIISynchronizedPrintf(pcbddc->dbg_viewer,"Subdomain %04d infinity error for Dirichlet nullspace correction solver: %1.14e\n",PetscGlobalRank,test_err);CHKERRQ(ierr); 249 } else { 250 ierr = PetscViewerASCIISynchronizedPrintf(pcbddc->dbg_viewer,"Subdomain %04d infinity error for Neumann nullspace correction solver: %1.14e\n",PetscGlobalRank,test_err);CHKERRQ(ierr); 251 } 252 253 ierr = MatTransposeMatMult(shell_ctx->Lbasis_mat,shell_ctx->Kbasis_mat,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&test_mat);CHKERRQ(ierr); 254 ierr = MatShift(test_mat,1.);CHKERRQ(ierr); 255 ierr = MatNorm(test_mat,NORM_INFINITY,&test_err);CHKERRQ(ierr); 256 ierr = MatDestroy(&test_mat);CHKERRQ(ierr); 257 if (isdir) { 258 ierr = PetscViewerASCIISynchronizedPrintf(pcbddc->dbg_viewer,"Subdomain %04d infinity error for Dirichlet nullspace matrices: %1.14e\n",PetscGlobalRank,test_err);CHKERRQ(ierr); 259 } else { 260 ierr = PetscViewerASCIISynchronizedPrintf(pcbddc->dbg_viewer,"Subdomain %04d infinity error for Neumann nullspace matrices: %1.14e\n",PetscGlobalRank,test_err);CHKERRQ(ierr); 261 } 262 263 /* Create ksp object suitable for extreme eigenvalues' estimation */ 264 ierr = KSPCreate(PETSC_COMM_SELF,&check_ksp);CHKERRQ(ierr); 265 ierr = KSPSetErrorIfNotConverged(check_ksp,pc->erroriffailure);CHKERRQ(ierr); 266 ierr = KSPSetOperators(check_ksp,local_mat,local_mat);CHKERRQ(ierr); 267 ierr = KSPSetTolerances(check_ksp,1.e-10,1.e-8,PETSC_DEFAULT,PETSC_DEFAULT);CHKERRQ(ierr); 268 ierr = KSPSetComputeSingularValues(check_ksp,PETSC_TRUE);CHKERRQ(ierr); 269 ierr = MatIsSymmetricKnown(pc->pmat,&setsym,&issym);CHKERRQ(ierr); 270 if (issym) { 271 ierr = KSPSetType(check_ksp,KSPCG);CHKERRQ(ierr); 272 } 273 ierr = KSPSetPC(check_ksp,check_pc);CHKERRQ(ierr); 274 ierr = KSPSetUp(check_ksp);CHKERRQ(ierr); 275 ierr = VecSetRandom(work1,NULL);CHKERRQ(ierr); 276 ierr = MatMult(local_mat,work1,work2);CHKERRQ(ierr); 277 ierr = KSPSolve(check_ksp,work2,work2);CHKERRQ(ierr); 278 ierr = VecAXPY(work2,-1.,work1);CHKERRQ(ierr); 279 ierr = VecNorm(work2,NORM_INFINITY,&test_err);CHKERRQ(ierr); 280 ierr = KSPComputeExtremeSingularValues(check_ksp,&lambda_max,&lambda_min);CHKERRQ(ierr); 281 ierr = KSPGetIterationNumber(check_ksp,&k);CHKERRQ(ierr); 282 if (isdir) { 283 ierr = PetscViewerASCIISynchronizedPrintf(pcbddc->dbg_viewer,"Subdomain %04d infinity error for Dirichlet adapted KSP (scale %d) %1.14e (it %d, eigs %1.6e %1.6e)\n",PetscGlobalRank,shell_ctx->apply_scaling,test_err,k,lambda_min,lambda_max);CHKERRQ(ierr); 284 } else { 285 ierr = PetscViewerASCIISynchronizedPrintf(pcbddc->dbg_viewer,"Subdomain %04d infinity error for Neumann adapted KSP (scale %d) %1.14e (it %d, eigs %1.6e %1.6e)\n",PetscGlobalRank,shell_ctx->apply_scaling,test_err,k,lambda_min,lambda_max);CHKERRQ(ierr); 286 } 287 ierr = KSPDestroy(&check_ksp);CHKERRQ(ierr); 288 ierr = VecDestroy(&work1);CHKERRQ(ierr); 289 ierr = VecDestroy(&work2);CHKERRQ(ierr); 290 ierr = VecDestroy(&work3);CHKERRQ(ierr); 291 PetscFunctionReturn(0); 292 } 293