neumann_values_zero.m

function FNneu = neumann_values_zero(glob,U,normals,params)
%function FNneu = neumann_values_zero(glob,U,normals,params)
%
% function computing neuman-values by pointwise evaluation. 
%
% glob: columnwise coordinate vectors of global points to be evaluated
% Uneu: columnwise U values in points in case of a u-dependent flux
% normals: Columnwise corresponding unit normal vectors
% 
% FNneu = 0, arguments except glob may be ignored
%
% Function supports affine decomposition, i.e. different operation modes
% guided by optional field decomp_mode in params. See also the
% contents.txt for general explanation

% Bernard Haasdonk 3.9.2009

% determine affine_decomposition_mode as integer  
% glob column check
% normals column check
if params.debug
  if ~isempty(normals) && size(glob,1) < size(glob,2)
    warning('coordinates in variable normals are given row-wise, but expected them to be column-wise');
    if params.debug > 2
      keyboard;
    end
  end
end
if params.debug
  if ~isempty(glob) && size(glob,1) < size(glob,2)
    warning('coordinates in variable glob are given row-wise, but expected them to be column-wise');
    if params.debug > 2
      keyboard;
    end
  end
end
decomp_mode = params.decomp_mode;

if decomp_mode == 2
  % cannot detect, whether any points will be available later,
  % so at least one component must be available.
  FNneu = 0;
elseif decomp_mode == 1
  % cannot detect in mode 2, whether any points will be available later,
  % so at least one component must be available.      
  FNneu = {[]};
elseif decomp_mode == 0
  FNneu = zeros(size(glob,1),1);
else
  error('unknown decomposition mode');
end;
%| \docupdate