CostFct4DVar.h

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/*
 * (C) Copyright 2009-2016 ECMWF.
 * (C) Copyright 2020-2021 UCAR.
 *
 * This software is licensed under the terms of the Apache Licence Version 2.0
 * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
 * In applying this licence, ECMWF does not waive the privileges and immunities
 * granted to it by virtue of its status as an intergovernmental organisation nor
 * does it submit to any jurisdiction.
 */
 
#ifndef OOPS_ASSIMILATION_COSTFCT4DVAR_H_
#define OOPS_ASSIMILATION_COSTFCT4DVAR_H_
 
#include <memory>
 
#include "eckit/config/LocalConfiguration.h"
#include "eckit/mpi/Comm.h"
#include "oops/assimilation/CostFunction.h"
#include "oops/assimilation/CostJb3D.h"
#include "oops/assimilation/CostJcDFI.h"
#include "oops/assimilation/CostJo.h"
#include "oops/assimilation/CostTermBase.h"
#include "oops/base/Geometry.h"
#include "oops/base/Increment.h"
#include "oops/base/LinearModel.h"
#include "oops/base/LinearVariableChangeBase.h"
#include "oops/base/Model.h"
#include "oops/base/PostProcessor.h"
#include "oops/base/PostProcessorTLAD.h"
#include "oops/base/State.h"
#include "oops/base/StateInfo.h"
#include "oops/base/TrajectorySaver.h"
#include "oops/base/Variables.h"
#include "oops/interface/VariableChange.h"
#include "oops/util/DateTime.h"
#include "oops/util/Duration.h"
#include "oops/util/Logger.h"
 
namespace oops {
 
/// Strong Constraint 4D-Var Cost Function
/*!
 * This class is not really necessary since it is only a special
 * case of the more general weak constraint 4D-Var cost function
 * with one sub-window. It is provided for readability.
 */
 
// -----------------------------------------------------------------------------
 
template<typename MODEL, typename OBS> class CostFct4DVar : public CostFunction<MODEL, OBS> {
  typedef Increment<MODEL>                Increment_;
  typedef ControlIncrement<MODEL, OBS>    CtrlInc_;
  typedef ControlVariable<MODEL, OBS>     CtrlVar_;
  typedef CostFunction<MODEL, OBS>        CostFct_;
  typedef Geometry<MODEL>                 Geometry_;
  typedef State<MODEL>                    State_;
  typedef Model<MODEL>                    Model_;
  typedef LinearModel<MODEL>              LinearModel_;
  typedef VariableChange<MODEL>           VarCha_;
  typedef LinearVariableChangeBase<MODEL> LinVarCha_;
 
 public:
  CostFct4DVar(const eckit::Configuration &, const eckit::mpi::Comm &);
  ~CostFct4DVar() {}
 
  void runTLM(CtrlInc_ &, PostProcessorTLAD<MODEL> &,
              PostProcessor<Increment_>,
              const bool idModel = false) const override;
  void runADJ(CtrlInc_ &, PostProcessorTLAD<MODEL> &,
              PostProcessor<Increment_>,
              const bool idModel = false) const override;
  void zeroAD(CtrlInc_ &) const override;
 
  void runNL(CtrlVar_ &, PostProcessor<State_>&) const override;
 
 private:
  void addIncr(CtrlVar_ &, const CtrlInc_ &, PostProcessor<Increment_>&) const override;
 
  CostJb3D<MODEL>     * newJb(const eckit::Configuration &, const Geometry_ &,
                              const CtrlVar_ &) const override;
  CostJo<MODEL, OBS>       * newJo(const eckit::Configuration &) const override;
  CostTermBase<MODEL, OBS> * newJc(const eckit::Configuration &, const Geometry_ &) const override;
  void doLinearize(const Geometry_ &, const eckit::Configuration &,
                   const CtrlVar_ &, const CtrlVar_ &,
                   PostProcessor<State_> &, PostProcessorTLAD<MODEL> &) override;
  const Geometry_ & geometry() const override {return resol_;}
 
  util::Duration windowLength_;
  util::DateTime windowBegin_;
  util::DateTime windowEnd_;
  const eckit::mpi::Comm & comm_;
  Geometry_ resol_;
  Model_ model_;
  const Variables ctlvars_;
  std::shared_ptr<LinearModel_> tlm_;
  VarCha_ an2model_;
  std::unique_ptr<LinVarCha_> inc2model_;
};
 
// =============================================================================
 
template<typename MODEL, typename OBS>
CostFct4DVar<MODEL, OBS>::CostFct4DVar(const eckit::Configuration & config,
                                       const eckit::mpi::Comm & comm)
  : CostFunction<MODEL, OBS>::CostFunction(config), comm_(comm),
    resol_(eckit::LocalConfiguration(config, "geometry"), comm),
    model_(resol_, eckit::LocalConfiguration(config, "model")),
    ctlvars_(config, "analysis variables"), tlm_(), an2model_(resol_, config),
    inc2model_()
{
  Log::trace() << "CostFct4DVar:CostFct4DVar" << std::endl;
  windowLength_ = util::Duration(config.getString("window length"));
  windowBegin_ = util::DateTime(config.getString("window begin"));
  windowEnd_ = windowBegin_ + windowLength_;
  this->setupTerms(config);
  // ASSERT(ctlvars_ <= this->background().state().variables());
  Log::trace() << "CostFct4DVar constructed" << std::endl;
}
 
// -----------------------------------------------------------------------------
 
template <typename MODEL, typename OBS>
CostJb3D<MODEL> * CostFct4DVar<MODEL, OBS>::newJb(const eckit::Configuration & jbConf,
                                                  const Geometry_ & resol,
                                                  const CtrlVar_ & xb) const {
  return new CostJb3D<MODEL>(jbConf, resol, ctlvars_, windowLength_, xb.state());
}
 
// -----------------------------------------------------------------------------
 
template <typename MODEL, typename OBS>
CostJo<MODEL, OBS> * CostFct4DVar<MODEL, OBS>::newJo(const eckit::Configuration & joConf) const {
  return new CostJo<MODEL, OBS>(joConf, comm_, windowBegin_, windowEnd_);
}
 
// -----------------------------------------------------------------------------
 
template <typename MODEL, typename OBS>
CostTermBase<MODEL, OBS> * CostFct4DVar<MODEL, OBS>::newJc(const eckit::Configuration & jcConf,
                                                           const Geometry_ & resol) const {
  const eckit::LocalConfiguration jcdfi(jcConf, "jcdfi");
  const util::DateTime vt(windowBegin_ + windowLength_/2);
  return new CostJcDFI<MODEL, OBS>(jcdfi, resol, vt, windowLength_);
}
 
// -----------------------------------------------------------------------------
 
template <typename MODEL, typename OBS>
void CostFct4DVar<MODEL, OBS>::runNL(CtrlVar_ & xx, PostProcessor<State_> & post) const {
  ASSERT(xx.state().validTime() == windowBegin_);
 
  State_ xm(xx.state().geometry(), model_.variables(), windowBegin_);
  an2model_.changeVar(xx.state(), xm);
  model_.forecast(xm, xx.modVar(), windowLength_, post);
  an2model_.changeVarInverse(xm, xx.state());
 
  ASSERT(xx.state().validTime() == windowEnd_);
}
 
// -----------------------------------------------------------------------------
 
template<typename MODEL, typename OBS>
void CostFct4DVar<MODEL, OBS>::doLinearize(const Geometry_ & resol,
                                           const eckit::Configuration & innerConf,
                                           const CtrlVar_ & bg, const CtrlVar_ & fg,
                                           PostProcessor<State_> & pp,
                                           PostProcessorTLAD<MODEL> & pptraj) {
  Log::trace() << "CostFct4DVar::doLinearize start" << std::endl;
  eckit::LocalConfiguration conf(innerConf, "linear model");
// Setup linear model (and trajectory)
  tlm_.reset(new LinearModel_(resol, conf));
  pp.enrollProcessor(new TrajectorySaver<MODEL>(conf, resol, fg.modVar(), tlm_, pptraj));
 
// Setup change of variables
  inc2model_.reset(LinearVariableChangeFactory<MODEL>::create(bg.state(), fg.state(),
                                                              resol, conf));
  inc2model_->setInputVariables(ctlvars_);
  Log::trace() << "CostFct4DVar::doLinearize done" << std::endl;
}
 
// -----------------------------------------------------------------------------
 
template <typename MODEL, typename OBS>
void CostFct4DVar<MODEL, OBS>::runTLM(CtrlInc_ & dx,
                                      PostProcessorTLAD<MODEL> & cost,
                                      PostProcessor<Increment_> post,
                                      const bool idModel) const {
  inc2model_->setOutputVariables(tlm_->variables());
 
  ASSERT(dx.state().validTime() == windowBegin_);
 
  Increment_ dxmodel(dx.state().geometry(), tlm_->variables(), windowBegin_);
  inc2model_->multiply(dx.state(), dxmodel);
  tlm_->forecastTL(dxmodel, dx.modVar(), windowLength_, post, cost, idModel);
  inc2model_->multiplyInverse(dxmodel, dx.state());
 
  ASSERT(dx.state().validTime() == windowEnd_);
}
 
// -----------------------------------------------------------------------------
 
template <typename MODEL, typename OBS>
void CostFct4DVar<MODEL, OBS>::zeroAD(CtrlInc_ & dx) const {
  dx.state().zero(windowEnd_);
  dx.modVar().zero();
  dx.obsVar().zero();
}
 
// -----------------------------------------------------------------------------
 
template <typename MODEL, typename OBS>
void CostFct4DVar<MODEL, OBS>::runADJ(CtrlInc_ & dx,
                                      PostProcessorTLAD<MODEL> & cost,
                                      PostProcessor<Increment_> post,
                                      const bool idModel) const {
  ASSERT(dx.state().validTime() == windowEnd_);
 
  Increment_ dxmodel(dx.state().geometry(), tlm_->variables(), windowEnd_);
  inc2model_->setOutputVariables(tlm_->variables());
  inc2model_->multiplyInverseAD(dx.state(), dxmodel);
  tlm_->forecastAD(dxmodel, dx.modVar(), windowLength_, post, cost, idModel);
  inc2model_->multiplyAD(dxmodel, dx.state());
 
  ASSERT(dx.state().validTime() == windowBegin_);
}
 
// -----------------------------------------------------------------------------
 
template<typename MODEL, typename OBS>
void CostFct4DVar<MODEL, OBS>::addIncr(CtrlVar_ & xx, const CtrlInc_ & dx,
                                       PostProcessor<Increment_> &) const {
  xx.state() += dx.state();
}
 
// -----------------------------------------------------------------------------
 
}  // namespace oops
 
#endif  // OOPS_ASSIMILATION_COSTFCT4DVAR_H_