贝叶斯网络的matlab实现。可以创建贝叶斯网络、训练模型

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