ReducedModel.m

classdef ReducedModel < Greedy.User.IReducedModel
  % reduced model for linear evolution problems as given by a
  % LinEvol.DetailedModel.
  %
  % This is compatible with Greedy.User.IReducedModel and can therefore make
  % use of @ref Greedy.User.IDetailedData "detailed data objects" created by
  % Greedy algorithms.

  properties
    enable_error_estimator = true;
  end

  properties(Constant)
    % This constant is used for a consistency check of the model descr with
    % help of IModel.struct_check()
    ddescr_checks = struct(...
      'operators_ptr',         {{@(x) isequal(class(x), 'function_handle')}},...
      'init_values_algorithm', {{@(x) isequal(class(x), 'function_handle')}},...
      'error_norm',            {{@ischar, 'values', {'l2', 'energy'} }}...
      );
  end

  methods
    function rm = ReducedModel(dmodel, bg_descr)
      % function rm = ReducedModel(detailed_model, basis_generator)
      % Constructor for the reduced model.
      %
      % Parameters:
      %   dmodel: of type LinEvol.DetailedModel

      if nargin == 1 || isempty(bg_descr)
        bg_descr = [];
      end
      % this implements a copy constructor if necessary...
      rm = rm@Greedy.User.IReducedModel(dmodel, bg_descr);
      % are we NOT a copy constructor?
      if ~(isempty(bg_descr) || isa(dmodel, 'LinEvol.ReducedModel'))
        if ~IModel.struct_check(dmodel.descr, ...
                                LinEvol.ReducedModel.ddescr_checks);
          error('Consistency check for LinEvol.ReducedModel failed.');
        end
      end
    end

    function a0 = rb_init_values(this, detailed_data, decomp_mode)
    % function a0 = rb_init_values(this, detailed_data, decomp_mode)
    % @copybrief rb_init_values_separable()
    %
    % This calls rb_init_values_separable().
    %
    % Parameters:
    %   detailed_data: detailed data tree leaf object of type Greedy.DataTree.Detailed.RBLeafNode.
    %
    % Return values:
    %   a0: coefficient vector of size 'N x 1' for the initial values.
      a0 = rb_init_values_separable(this, detailed_data, decomp_mode);
    end

    %
    %
    % Parameters:
    %   reduced_data: of type LinEvol.ReducedData
    rb_sim_data = rb_simulation_impl(this, reduced_data);

    function rb_sim_data = rb_reconstruction(this, detailed_data, rb_sim_data)
    % function rb_sim_data = rb_reconstruction(this, detailed_data, rb_sim_data)
    % @copybrief rb_reconstruction_default()
    %
    % This calls rb_reconstruction_default().
    %
    % Parameters:
    %   detailed_data: of type LinEvol.DetailedData
    %   rb_sim_data:   struct holding reduced simulation data returned by
    %                  IReducedModel.rb_simulation() .
    %
    % Return values:
    %   rb_sim_data: struct holding the reduced simulation results and their
    %                reconstructions.
      if isa(detailed_data, 'Greedy.User.IDetailedData')
        dd_leaf = get_leaf(detailed_data, this);
      else
        dd_leaf = detailed_data;
      end
      rb_sim_data = rb_reconstruction_default(this, dd_leaf, rb_sim_data);
    end

    function c = copy(this)
      % function c = copy(this)
      % @copybrief IReducedModelcopy()
      %
      % Return values:
      %   c:   an object of type LinEvol.ReducedModel which is a deep copy of this object.
      c = ReducedModel(this);
    end

  end
  methods (Static)
    function Delta        = get_estimators_from_sim_data(rb_sim_data)
      % function Delta        = get_estimators_from_sim_data(sim_data)
      % @copybrief IReducedModelget_estimators_from_sim_data()
      %
      % @copydetails IReducedModelget_estimators_from_sim_data()
      Delta = rb_sim_data.Delta;
    end

    function Delta        = get_estimator_from_sim_data(rb_sim_data)
      % function Delta        = get_estimator_from_sim_data(sim_data)
      % @copybrief IReducedModelget_estimator_from_sim_data()
      %
      % @copydetails IReducedModelget_estimator_from_sim_data()
      Delta = rb_sim_data.Delta(end);
    end

  end
end