Line data    Source code

       1             : // rbOOmit: An implementation of the Certified Reduced Basis method.
       2             : // Copyright (C) 2009, 2010 David J. Knezevic
       3             : 
       4             : // This file is part of rbOOmit.
       5             : 
       6             : // rbOOmit is free software; you can redistribute it and/or
       7             : // modify it under the terms of the GNU Lesser General Public
       8             : // License as published by the Free Software Foundation; either
       9             : // version 2.1 of the License, or (at your option) any later version.
      10             : 
      11             : // rbOOmit is distributed in the hope that it will be useful,
      12             : // but WITHOUT ANY WARRANTY; without even the implied warranty of
      13             : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      14             : // Lesser General Public License for more details.
      15             : 
      16             : // You should have received a copy of the GNU Lesser General Public
      17             : // License along with this library; if not, write to the Free Software
      18             : // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
      19             : 
      20             : #ifndef LIBMESH_TRANSIENT_RB_EVALUATION_H
      21             : #define LIBMESH_TRANSIENT_RB_EVALUATION_H
      22             : 
      23             : // rbOOmit includes
      24             : #include "libmesh/rb_evaluation.h"
      25             : #include "libmesh/rb_temporal_discretization.h"
      26             : 
      27             : // libMesh includes
      28             : 
      29             : // C++ includes
      30             : 
      31             : namespace libMesh
      32             : {
      33             : 
      34             : class TransientRBThetaExpansion;
      35             : 
      36             : /**
      37             :  * This class is part of the rbOOmit framework.
      38             :  *
      39             :  * TransientRBEvaluation extends RBEvaluation to
      40             :  * encapsulate the code and data required
      41             :  * to perform "online" RB evaluations for
      42             :  * Linear Time Invariant (LTI) transient problems.
      43             :  *
      44             :  * We can handle time controls on the RHS as h(t)*f(x,\f$ \mu \f$).
      45             :  * See Martin Grepl's thesis for more details.
      46             :  *
      47             :  * \author David J. Knezevic
      48             :  * \date 2011
      49             :  */
      50          32 : class TransientRBEvaluation : public RBEvaluation, public RBTemporalDiscretization
      51             : {
      52             : public:
      53             : 
      54             :   /**
      55             :    * Constructor.
      56             :    */
      57             :   TransientRBEvaluation (const Parallel::Communicator & comm_in);
      58             : 
      59             :   /**
      60             :    * Special functions.
      61             :    * - This class contains unique_ptrs, so it can't be default copy
      62             :    *   constructed/assigned.
      63             :    * - The destructor is defaulted out of line.
      64             :    */
      65             :   TransientRBEvaluation (TransientRBEvaluation &&) = default;
      66             :   TransientRBEvaluation (const TransientRBEvaluation &) = delete;
      67             :   TransientRBEvaluation & operator= (const TransientRBEvaluation &) = delete;
      68             :   TransientRBEvaluation & operator= (TransientRBEvaluation &&) = default;
      69             :   virtual ~TransientRBEvaluation ();
      70             : 
      71             :   /**
      72             :    * The type of the parent.
      73             :    */
      74             :   typedef RBEvaluation Parent;
      75             : 
      76             :   /**
      77             :    * Clear this TransientRBEvaluation object.
      78             :    * Override to also clear the M_q representors
      79             :    */
      80             :   virtual void clear() override;
      81             : 
      82             :   /**
      83             :    * Resize and clear the data vectors corresponding to the
      84             :    * value of \p Nmax. Optionally resize the data structures
      85             :    * required for the error bound.
      86             :    * Overridden to resize data relevant in the time-dependent
      87             :    * case.
      88             :    */
      89             :   virtual void resize_data_structures(const unsigned int Nmax,
      90             :                                       bool resize_error_bound_data=true) override;
      91             : 
      92             :   /**
      93             :    * Perform online solve for current_params
      94             :    * with the N basis functions. Overridden
      95             :    * to perform a time-dependent solve.
      96             :    */
      97             :   using RBEvaluation::rb_solve;
      98             :   virtual Real rb_solve(unsigned int N) override;
      99             : 
     100             :   /**
     101             :    * If a solve has already been performed, then we cached some data
     102             :    * and we can perform a new solve much more rapidly
     103             :    * (with the same parameters but a possibly different initial condition/rhs control).
     104             :    */
     105             :   virtual Real rb_solve_again();
     106             : 
     107             :   /**
     108             :    * \returns A scaling factor that we can use to provide a consistent
     109             :    * scaling of the RB error bound across different parameter values.
     110             :    */
     111             :   virtual Real get_error_bound_normalization() override;
     112             : 
     113             :   /**
     114             :    * Specifies the residual scaling on the numerator to
     115             :    * be used in the a posteriori error bound. Override
     116             :    * in subclass in order to obtain the desired error bound.
     117             :    */
     118             :   virtual Real residual_scaling_numer(Real alpha_LB);
     119             : 
     120             :   /**
     121             :    * Compute the dual norm of the residual for the solution
     122             :    * saved in RB_solution. This function uses the cached time-independent
     123             :    * data.
     124             :    */
     125             :   using RBEvaluation::compute_residual_dual_norm;
     126             :   virtual Real compute_residual_dual_norm(const unsigned int N) override;
     127             : 
     128             :   /**
     129             :    * Compute the dual norm of the residual for the solution
     130             :    * saved in RB_solution. This function does not used the cached
     131             :    * data and therefore also works when the parameter changes as
     132             :    * a function of time.
     133             :    */
     134             :   virtual Real uncached_compute_residual_dual_norm(const unsigned int N);
     135             : 
     136             :   /**
     137             :    * Helper function for caching the terms in the
     138             :    * online residual assembly that do not change in time.
     139             :    * (This is only useful when the parameter is fixed in time.)
     140             :    */
     141             :   void cache_online_residual_terms(const unsigned int N);
     142             : 
     143             :   /**
     144             :    * Clear all the Riesz representors that are used to compute the RB residual
     145             :    * (and hence error bound). This is useful since once we complete the Greedy
     146             :    * we may not need the representors any more.
     147             :    * Override to clear the M_q representors.
     148             :    */
     149             :   virtual void clear_riesz_representors() override;
     150             : 
     151             :   /**
     152             :    * Write out all the data to text files in order to segregate the
     153             :    * Offline stage from the Online stage.
     154             :    *
     155             :    * \note This is a legacy method, use RBDataSerialization instead.
     156             :    */
     157             :   virtual void legacy_write_offline_data_to_files(const std::string & directory_name = "offline_data",
     158             :                                                   const bool write_binary_data=true) override;
     159             : 
     160             :   /**
     161             :    * Read in the saved Offline reduced basis data
     162             :    * to initialize the system for Online solves.
     163             :    *
     164             :    * \note This is a legacy method, use RBDataSerialization instead.
     165             :    */
     166             :   virtual void legacy_read_offline_data_from_files(const std::string & directory_name = "offline_data",
     167             :                                                    bool read_error_bound_data=true,
     168             :                                                    const bool read_binary_data=true) override;
     169             : 
     170             :   //----------- PUBLIC DATA MEMBERS -----------//
     171             : 
     172             :   /**
     173             :    * Dense RB L2 matrix.
     174             :    */
     175             :   DenseMatrix<Number> RB_L2_matrix;
     176             : 
     177             :   /**
     178             :    * Cached data for subsequent solves.
     179             :    */
     180             :   DenseMatrix<Number> RB_LHS_matrix;
     181             :   DenseMatrix<Number> RB_RHS_matrix;
     182             :   DenseVector<Number> RB_RHS_save;
     183             : 
     184             :   /**
     185             :    * Dense matrices for the RB mass matrices.
     186             :    */
     187             :   std::vector<DenseMatrix<Number>> RB_M_q_vector;
     188             : 
     189             :   /**
     190             :    * The RB outputs for all time-levels from the
     191             :    * most recent rb_solve.
     192             :    */
     193             :   std::vector<std::vector<Number>> RB_outputs_all_k;
     194             : 
     195             :   /**
     196             :    * The error bounds for each RB output for all
     197             :    * time-levels from the most recent rb_solve.
     198             :    */
     199             :   std::vector<std::vector<Real>> RB_output_error_bounds_all_k;
     200             : 
     201             :   /**
     202             :    * The RB solution at the previous time-level.
     203             :    */
     204             :   DenseVector<Number> old_RB_solution;
     205             : 
     206             :   /**
     207             :    * Array storing the solution data at each time level from the most recent solve.
     208             :    */
     209             :   std::vector<DenseVector<Number>> RB_temporal_solution_data;
     210             : 
     211             :   /**
     212             :    * The error bound data for all time-levels from the
     213             :    * most recent rb_solve.
     214             :    */
     215             :   std::vector<Real > error_bound_all_k;
     216             : 
     217             :   /**
     218             :    * Vector storing initial L2 error for all
     219             :    * 1 <= N <= RB_size.
     220             :    */
     221             :   std::vector<Real> initial_L2_error_all_N;
     222             : 
     223             :   /**
     224             :    * The RB initial conditions (i.e. L2 projection of the truth
     225             :    * initial condition) for each N.
     226             :    */
     227             :   std::vector<DenseVector<Number>> RB_initial_condition_all_N;
     228             : 
     229             :   /**
     230             :    * Vectors storing the residual representor inner products
     231             :    * to be used in computing the residuals online.
     232             :    */
     233             :   std::vector<std::vector<std::vector<Number>>> Fq_Mq_representor_innerprods;
     234             :   std::vector<std::vector<std::vector<Number>>> Mq_Mq_representor_innerprods;
     235             :   std::vector<std::vector<std::vector<std::vector<Number>>>> Aq_Mq_representor_innerprods;
     236             : 
     237             : 
     238             :   /**
     239             :    * Cached residual terms. These can be used to accelerate residual calculations
     240             :    * when we have an LTI system.
     241             :    */
     242             :   Number cached_Fq_term;
     243             :   DenseVector<Number> cached_Fq_Aq_vector;
     244             :   DenseMatrix<Number> cached_Aq_Aq_matrix;
     245             :   DenseVector<Number> cached_Fq_Mq_vector;
     246             :   DenseMatrix<Number> cached_Aq_Mq_matrix;
     247             :   DenseMatrix<Number> cached_Mq_Mq_matrix;
     248             : 
     249             :   /**
     250             :    * Vector storing the mass matrix representors.
     251             :    * These are basis dependent and hence stored here.
     252             :    */
     253             :   std::vector<std::vector<std::unique_ptr<NumericVector<Number>>>> M_q_representor;
     254             : 
     255             :   /**
     256             :    * Check that the data has been cached in case of using rb_solve_again
     257             :    */
     258             :   bool _rb_solve_data_cached;
     259             : };
     260             : 
     261             : }
     262             : 
     263             : #endif // LIBMESH_TRANSIENT_RB_EVALUATION_H