rhs_robin.m

function res = rhs_robin(x, model, df_info, i, elind, edgeind)
%function res = rhs_robin(x, model, df_info, i, elind, edgeind)
%
% auxiliary function for integral kernel for r_robin
% integral kernel on all robin-edges simultaneously
% here x is a scalar value on unit interval
% f(x) = g_R/beta * hatphi_i  
% multiplication with |edge| is realized in caller after quadrature.
% function can handle cell-array valued data

% B. Haasdonk 22.2.2011
% IM 21.07.2016

res = zeros(0,1);
for local_edge_id = 1:3
  lcoord = llocal2local(df_info.grid,local_edge_id,x); % local coord for x on edge 1    
  hat_phi_i = evaluate_basis_function(df_info,lcoord,i);
  elinds = elind(edgeind==local_edge_id);
  beta = model.robin_beta(df_info.grid,elinds,local_edge_id,x,model); ...
  % local model!
  g_R = cache_function(@(xelind, xlocal_edge_ind, xarg, xmodel)...
                       xmodel.robin_values(...
                           df_info.grid, xelind, xlocal_edge_ind, ...
                           xarg, xmodel), ...
                       elinds, local_edge_id, x, model);
  if ~iscell(g_R)
    res = [res;...
           (beta.^(-1)).*g_R * hat_phi_i; ...
        ];
  else % iscell!!
    if ~iscell(res)
      res = cell(1,length(g_R));
      for q = 1:length(g_R);
        res{q} = zeros(0,1);
      end
    end
    for q = 1:length(g_R)
      res{q} = [res{q};...
                (beta.^(-1)).*g_R{q} * hat_phi_i; ...
               ];
    end
  end
end

end