wolffd@0: function lam = prod_lambda_msgs(n, cs, msg, msg_type, except)
wolffd@0: 
wolffd@0: if nargin < 5, except = -1; end
wolffd@0: 
wolffd@0: lam = msg{n}.lambda_from_self;
wolffd@0: switch msg_type
wolffd@0:   case 'd',
wolffd@0:    for i=1:length(cs)
wolffd@0:      c = cs(i);
wolffd@0:      if c ~= except
wolffd@0:        lam = lam .* msg{n}.lambda_from_child{i};
wolffd@0:      end
wolffd@0:    end  
wolffd@0:  case 'g',
wolffd@0:   if isinf(lam.precision) % isfield(lam, 'observed_val')
wolffd@0:     return; % pass on the observed msg
wolffd@0:   end
wolffd@0:    for i=1:length(cs)
wolffd@0:      c = cs(i);
wolffd@0:      if c ~= except
wolffd@0:        m = msg{n}.lambda_from_child{i};
wolffd@0:        lam.precision = lam.precision + m.precision;
wolffd@0:        lam.info_state = lam.info_state + m.info_state;
wolffd@0:      end
wolffd@0:    end  
wolffd@0: end
wolffd@0: 
wolffd@0: 
wolffd@0: