RbReducedDataNode.m

classdef RbReducedDataNode < Greedy.User.IReducedDataNode
  % Implementation of a Greedy.User.IReducedDataNode storing reduced data
  % depending on reduced basis space information only. (e.g. reduced matrices
  % of operators)

  properties
  
    id;
  
    % reduced basis mass matrix.
    %
    % The matrix entries are:
    % ``({ \bf N })_{ij} = \int \varphi_i \varphi_j``
    Nmass;
    
  end

  properties (SetAccess = private, Dependent)
    % @copybrief TwoPhaseFlow.EiRbReducedDataNode.N
    %
    % @copydetails TwoPhaseFlow.EiRbReducedDataNode.N
    N;
  end

  methods
    function rd = RbReducedDataNode(rmodel, detailed_data)
      % function rd = RbReducedDataNode(rmodel, detailed_data)
      % constructor for the generation of the reduced data.
      %
      % Parameters:
      %   rmodel: of type TwoPhaseFlow.ReducedModel
      %   detailed_data: of type IDetailedData
      %
      % Alternative synopsis:
      % @code RbReducedDataNode(rmodel, ei_reduced_data_node) @endcode copying
      % a reduced data node and (optionally) extracting smaller matrices.
      if nargin == 0
        error('TwoPhaseFlow.RbReducedDataNode constructor needs an argument');
      elseif nargin == 2 && isa(rmodel, 'IReducedModel') ...
          && isa(detailed_data, 'TwoPhaseFlow.RbReducedDataNode')
        copy   = detailed_data;
        copy_extract(rd, copy, rmodel);
      elseif nargin == 2
        fill_fields(rd, rmodel, detailed_data);
      else
        error('Did not find constructor for your arguments');
      end
    end

    function conds = get_conds(this)
      if ~isempty(this.Nmass)
        conds.Nmass = condest(this.Nmass);
      end
      if ~isempty(this.LL_I)
        conds.LL_I  = condest(this.LL_I);
      end
    end

    function N = get.N(this)
      N = size(this.Nmass,1);
    end

    function yesno = needs_subset_copy(this, rmodel)
      % function yesno = needs_subset_copy(this, rmodel)
      % @copybrief ::GreedyUser.IReducedDataNode.needs_subset_copy()
      %
      % @copydetails ::GreedyUser.IReducedDataNode.needs_subset_copy()
      %
      % Parameters:
      %   rmodel: of type TwoPhaseFlow.ReducedModel
      rn = get_by_description(rmodel.N, this.id);
      yesno = this.N ~= rn;
    end

  end
  methods(Access=private)

    function fill_fields(this, rmodel, detailed_data)

      this.id = detailed_data.id;
      model_data = detailed_data.model_data;

      N = get_by_description(rmodel.N, this.id);

      if size(detailed_data.RB, 1) == size(model_data.W,2)
        A          = model_data.W;
      else
        A          = model_data.diamondW;
      end

      this.Nmass = detailed_data.RB(:,1:N)' * A * detailed_data.RB(:,1:N);

    end

    function copy_extract(this, reduced_data, rmodel)

      % extract correct N-sized submatrices and subvectors from reduced_data
      rn = get_by_description(rmodel.N, reduced_data.id);
      this.id = reduced_data.id;
      if rn > reduced_data.N
        error('N too large for current size of reduced basis!');
      end

      N = rn;

      if ~isempty(reduced_data.Nmass)
        this.Nmass = reduced_data.Nmass(1:N,1:N);
      end

    end
  end

end