Random.m

classdef Random < SnapshotsGenerator.Cached
  % creates random Dof vectors (for testing purposes only!)

  properties
    % min-max vector indicating the range for the random values of the
    % generated Dof-values.
    ranges = [0 1];
  end

  methods
    function rdg = Random(dmodel, id, ranges, force_delete, enable_caching)
      %function rdg = Random(dmodel, id, ranges, force_delete, enable_caching)
      % constructor for the random detailed generator
      %
      % Parameters:
      %   id:             an identifier string
      %   force_delete:   boolean value indicating whether the cached data
      %                   shall be automatically deleted if its inconsistent
      %                   with the given 'dmodel'. (Default = 'true')
      %   enable_caching: boolean value indicating whether the generated data
      %                   shall be stored in a cache. (Default = 'true')
      %   ranges:         min-max vector indicating the range for the random
      %                   values of the generated Dof-values. (Default = [0 1])
      if nargin < 2 || isempty(id)
        id = 'random';
      end
      if nargin < 4
        force_delete = [];
      end
      if nargin < 5
        enable_caching = [];
      end
      rdg = rdg@SnapshotsGenerator.Cached(dmodel, id, force_delete, enable_caching);
      if nargin >= 3 && ~isempty(ranges)
        rdg.ranges = ranges;
      end
    end

  end

  methods (Access = protected)
    function [U, opt_fields] = generate_impl(this, dmodel, detailed_data, fields)
      if isa(detailed_data, 'Greedy.DataTree.Detailed.INode')
        model_data = detailed_data.model_data;
      else
        model_data = detailed_data;
      end
      nelems = model_data.grid.nelements;
      hashstring = this.hashcode(dmodel);
      hash       = sscanf(hashstring(1:6), '%x');
      rand('twister', hash);
      if isfield(dmodel.descr, 'nt')
        nt = dmodel.nt;
      else
        nt = 0;
      end
      if ~isfield(dmodel.descr, 'subfields')
        U = rand(nelems, nt+1) * (this.ranges(2)-this.ranges(1))+this.ranges(1);
      else
        st = dmodel.descr.subfields;
        for i = 1:length(st)
          U.(st(i).shortname) = rand(st(i).length, nt+1) ...
            * (st(i).ranges(2)-st(i).ranges(1)) + st(i).ranges(1);
        end
      end
      opt_fields = [];
    end
  end
end