disc_init_values.m

function res = disc_init_values(model,model_data)
%function res = disc_init_values(model,model_data)
%
% function computing the init-value discrete function by
% l2projection of the init value function on the discrete function space
%
% in 'complete' mode a singe discrete function is produced,
% in 'components' mode, it is a cell array of discrete functions
% in 'coefficients' mode it is a vector of coefficients.

% Bernard Haasdonk 22.7.2006

if nargin ~= 2
  error('wrong number of parameters!');
end;

% affine decomposition is supported by init_data, so automatically
% satisfied.

decomp_mode = model.decomp_mode;

if decomp_mode == 2 % = coefficients
  res = model.init_values_ptr([],model);
elseif decomp_mode == 1 % = components
  % idea for improvement: method l2_project sequence: integration of a sequence
  % of functions  
  
  % the following is an expensive workaround
  params = model; 
  params.nelements = model_data.grid.nelements; 
  params.pdeg = model.pdeg;
  % determine dimrange
  tmp = model.init_values_ptr([0,0],model);
  params.dimrange = size(tmp{1},1); % possibly vectorial function

  Q_u0 = length(tmp);
  res = cell(1,Q_u0);
  for q = 1:Q_u0
    params.single_comp_index = q;
    f = @(einds,loc,grid,params) get_single_comp(...
        model.init_values_ptr(...
            local2global(grid,einds,loc,params),...
            params),...
        params); 
    res{q} = model.l2project(f,model.init_values_qdeg,model_data.grid, ...
                             params);
  end;
  
else % decomp_mode = 0 == complete
  params = model; 
  params.nelements = model_data.grid.nelements; 
  params.pdeg = model.pdeg;
  % determine dimrange
  tmp = model.init_values_ptr([0,0],model);
  params.dimrange = size(tmp,1); % possibly vectorial function
  %  f = @(einds,loc,grid,params) model.init_values_ptr(...
  %      local2global(grid,einds,loc,params),params); 
  f = @my_f;
  res = model.l2project(f, model.init_values_qdeg, model_data.grid, ...
                        params);
end;

% extract single array from cell array
function res = get_single_comp(cellarr,params)
res = cellarr{params.single_comp_index};

function res = my_f(einds,loc,grid,params) 
    res = params.init_values_ptr(local2global(grid,einds,loc,params),params);