dune-istl  2.3beta2
twolevelmethod.hh
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1 // -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
2 // vi: set et ts=4 sw=2 sts=2:
3 #ifndef DUNE_ISTL_TWOLEVELMETHOD_HH
4 #define DUNE_ISTL_TWOLEVELMETHOD_HH
5 
7 #include"amg.hh"
8 #include"galerkin.hh"
9 #include<dune/istl/solver.hh>
10 #include<dune/common/shared_ptr.hh>
11 #include<dune/common/unused.hh>
12 
20 namespace Dune
21 {
22 namespace Amg
23 {
24 
34 template<class FO, class CO>
36 {
37 public:
42  typedef FO FineOperatorType;
46  typedef typename FineOperatorType::range_type FineRangeType;
50  typedef typename FineOperatorType::domain_type FineDomainType;
55  typedef CO CoarseOperatorType;
59  typedef typename CoarseOperatorType::range_type CoarseRangeType;
63  typedef typename CoarseOperatorType::domain_type CoarseDomainType;
68  shared_ptr<CoarseOperatorType>& getCoarseLevelOperator()
69  {
70  return operator_;
71  }
77  {
78  return rhs_;
79  }
80 
86  {
87  return lhs_;
88  }
98  virtual void moveToCoarseLevel(const FineRangeType& fineRhs)=0;
108  virtual void moveToFineLevel(FineDomainType& fineLhs)=0;
116  virtual void createCoarseLevelSystem(const FineOperatorType& fineOperator)=0;
117 
119  virtual LevelTransferPolicy* clone() const =0;
120 
123 
124  protected:
130  shared_ptr<CoarseOperatorType> operator_;
131 };
132 
138 template<class O, class C>
140  : public LevelTransferPolicy<O,O>
141 {
143 public:
145  typedef C Criterion;
147 
149  : criterion_(crit)
150  {}
151 
152  void createCoarseLevelSystem(const O& fineOperator)
153  {
154  prolongDamp_ = criterion_.getProlongationDampingFactor();
157  typedef typename Dune::Amg::PropertiesGraph<MatrixGraph,Dune::Amg::VertexProperties,
158  Dune::Amg::EdgeProperties,Dune::IdentityMap,Dune::IdentityMap> PropertiesGraph;
159  MatrixGraph mg(fineOperator.getmat());
160  PropertiesGraph pg(mg,Dune::IdentityMap(),Dune::IdentityMap());
161  typedef NegateSet<typename ParallelInformation::OwnerSet> OverlapFlags;
162 
163  aggregatesMap_.reset(new AggregatesMap(pg.maxVertex()+1));
164 
165  int noAggregates, isoAggregates, oneAggregates, skippedAggregates;
166 
167  tie(noAggregates, isoAggregates, oneAggregates, skippedAggregates) =
168  aggregatesMap_->buildAggregates(fineOperator.getmat(), pg, criterion_, true);
169  std::cout<<"no aggregates="<<noAggregates<<" iso="<<isoAggregates<<" one="<<oneAggregates<<" skipped="<<skippedAggregates<<std::endl;
170  // misuse coarsener to renumber aggregates
172  typedef std::vector<bool>::iterator Iterator;
173  typedef Dune::IteratorPropertyMap<Iterator, Dune::IdentityMap> VisitedMap;
174  std::vector<bool> excluded(fineOperator.getmat().N(), false);
175  VisitedMap vm(excluded.begin(), Dune::IdentityMap());
176  ParallelInformation pinfo;
177  std::size_t aggregates = renumberer.coarsen(pinfo, pg, vm,
178  *aggregatesMap_, pinfo,
179  noAggregates);
180  std::vector<bool>& visited=excluded;
181 
182  typedef std::vector<bool>::iterator Iterator;
183 
184  for(Iterator iter= visited.begin(), end=visited.end();
185  iter != end; ++iter)
186  *iter=false;
187  matrix_.reset(productBuilder.build(mg, vm,
189  *aggregatesMap_,
190  aggregates,
191  OverlapFlags()));
192  productBuilder.calculate(fineOperator.getmat(), *aggregatesMap_, *matrix_, pinfo, OverlapFlags());
193  this->lhs_.resize(this->matrix_->M());
194  this->rhs_.resize(this->matrix_->N());
195  this->operator_.reset(new O(*matrix_));
196  }
197 
198  void moveToCoarseLevel(const typename FatherType::FineRangeType& fineRhs)
199  {
201  ::restrictVector(*aggregatesMap_, this->rhs_, fineRhs, ParallelInformation());
202  this->lhs_=0;
203  }
204 
206  {
208  ::prolongateVector(*aggregatesMap_, this->lhs_, fineLhs,
209  prolongDamp_, ParallelInformation());
210  }
211 
213  {
214  return new AggregationLevelTransferPolicy(*this);
215  }
216 
217 private:
218  typename O::matrix_type::field_type prolongDamp_;
219  shared_ptr<AggregatesMap> aggregatesMap_;
220  Criterion criterion_;
221  shared_ptr<typename O::matrix_type> matrix_;
222 };
223 
230 template<class O, class S, class C>
232 {
233 public:
235  typedef O Operator;
237  typedef typename O::range_type X;
239  typedef C Criterion;
241  typedef S Smoother;
252  : smootherArgs_(args), criterion_(c)
253  {}
256  : coarseOperator_(other.coarseOperator_), smootherArgs_(other.smootherArgs_),
257  criterion_(other.criterion_)
258  {}
259 private:
266  struct AMGInverseOperator : public InverseOperator<X,X>
267  {
268  AMGInverseOperator(const typename AMGType::Operator& op,
269  const Criterion& crit,
270  const typename AMGType::SmootherArgs& args)
271  : amg_(op, crit,args), first_(true)
272  {}
273 
274  void apply(X& x, X& b, double reduction, InverseOperatorResult& res)
275  {
276  DUNE_UNUSED_PARAMETER(reduction);
277  DUNE_UNUSED_PARAMETER(res);
278  if(first_)
279  {
280  amg_.pre(x,b);
281  first_=false;
282  x_=x;
283  }
284  amg_.apply(x,b);
285  }
286 
287  void apply(X& x, X& b, InverseOperatorResult& res)
288  {
289  return apply(x,b,1e-8,res);
290  }
291 
292  ~AMGInverseOperator()
293  {
294  if(!first_)
295  amg_.post(x_);
296  }
297  AMGInverseOperator(const AMGInverseOperator& other)
298  : x_(other.x_), amg_(other.amg_), first_(other.first_)
299  {
300  }
301  private:
302  X x_;
303  AMGType amg_;
304  bool first_;
305  };
306 
307 public:
309  typedef AMGInverseOperator CoarseLevelSolver;
310 
318  template<class P>
320  {
321  coarseOperator_=transferPolicy.getCoarseLevelOperator();
322  AMGInverseOperator* inv = new AMGInverseOperator(*coarseOperator_,
323  criterion_,
324  smootherArgs_);
325 
326  return inv; //shared_ptr<InverseOperator<X,X> >(inv);
327 
328  }
329 
330 private:
332  shared_ptr<Operator> coarseOperator_;
334  SmootherArgs smootherArgs_;
336  Criterion criterion_;
337 };
338 
344 template<class FO, class CSP, class S>
346  public Preconditioner<typename FO::domain_type, typename FO::range_type>
347 {
348 public:
352  typedef typename CoarseLevelSolverPolicy::CoarseLevelSolver CoarseLevelSolver;
357  typedef FO FineOperatorType;
361  typedef typename FineOperatorType::range_type FineRangeType;
365  typedef typename FineOperatorType::domain_type FineDomainType;
370  typedef typename CSP::Operator CoarseOperatorType;
374  typedef typename CoarseOperatorType::range_type CoarseRangeType;
378  typedef typename CoarseOperatorType::domain_type CoarseDomainType;
382  typedef S SmootherType;
383  // define the category
384  enum {
387  };
388 
404  shared_ptr<SmootherType> smoother,
406  CoarseOperatorType>& policy,
407  CoarseLevelSolverPolicy& coarsePolicy,
408  std::size_t preSteps=1, std::size_t postSteps=1)
409  : operator_(&op), smoother_(smoother),
410  preSteps_(preSteps), postSteps_(postSteps)
411  {
412  policy_ = policy.clone();
413  policy_->createCoarseLevelSystem(*operator_);
414  coarseSolver_=coarsePolicy.createCoarseLevelSolver(*policy_);
415  }
416 
418  : operator_(other.operator_), coarseSolver_(new CoarseLevelSolver(*other.coarseSolver_)),
419  smoother_(other.smoother_), policy_(other.policy_->clone()),
420  preSteps_(other.preSteps_), postSteps_(other.postSteps_)
421  {}
422 
424  {
425  // Each instance has its own policy.
426  delete policy_;
427  delete coarseSolver_;
428  }
429 
431  {
432  smoother_->pre(x,b);
433  }
434 
436  {
437  DUNE_UNUSED_PARAMETER(x);
438  }
439 
440  void apply(FineDomainType& v, const FineRangeType& d)
441  {
442  FineDomainType u(v);
443  FineRangeType rhs(d);
444  LevelContext context;
446  context.pinfo=&info;
447  context.lhs=&u;
448  context.update=&v;
449  context.smoother=smoother_;
450  context.rhs=&rhs;
451  context.matrix=operator_;
452  // Presmoothing
453  presmooth(context, preSteps_);
454  //Coarse grid correction
455  policy_->moveToCoarseLevel(*context.rhs);
457  coarseSolver_->apply(policy_->getCoarseLevelLhs(), policy_->getCoarseLevelRhs(), res);
458  *context.lhs=0;
459  policy_->moveToFineLevel(*context.lhs);
460  *context.update += *context.lhs;
461  // Postsmoothing
462  postsmooth(context, postSteps_);
463 
464  }
465 
466 private:
470  struct LevelContext
471  {
473  typedef S SmootherType;
475  shared_ptr<SmootherType> smoother;
477  FineDomainType* lhs;
478  /*
479  * @brief The right hand side holding the current residual.
480  *
481  * This is passed to the smoother as the right hand side.
482  */
483  FineRangeType* rhs;
489  FineDomainType* update;
491  SequentialInformation* pinfo;
497  const FineOperatorType* matrix;
498  };
499  const FineOperatorType* operator_;
501  CoarseLevelSolver* coarseSolver_;
503  shared_ptr<S> smoother_;
505  LevelTransferPolicy<FO,typename CSP::Operator>* policy_;
507  std::size_t preSteps_;
509  std::size_t postSteps_;
510 };
511 }// end namespace Amg
512 }// end namespace Dune
513 
515 #endif