thompson.patch

diff --git jubatus/core/bandit/bandit_factory_test.cpp jubatus/core/bandit/bandit_factory_test.cpp                                                                                                                                                                    
index 559b5be..a1117c6 100644                                                                                                                                                                                                                                         
--- jubatus/core/bandit/bandit_factory_test.cpp                                                                                                                                                                                                                       
+++ jubatus/core/bandit/bandit_factory_test.cpp                                                                                                                                                                                                                       
@@ -48,6 +48,7 @@ TEST(bandit_factory, ucb1) {
                                                                                                                                                                                                                                                                      
 TEST(bandit_factory, ts) {                                                                                                                                                                                                                                           
   json::json js(new json::json_object);                                                                                                                                                                                                                              
+  js["assume_unrewarded"] = json::to_json(true);                                                                                                                                                                                                                     
   common::jsonconfig::config conf(js);                                                                                                                                                                                                                               
   shared_ptr<bandit_base> p = bandit_factory::create("ts", conf);                                                                                                                                                                                                    
   EXPECT_EQ("ts", p->name());                                                                                                                                                                                                                                        
diff --git jubatus/core/bandit/ts.cpp jubatus/core/bandit/ts.cpp                                                                                                                                                                                                      
index b5c48d4..c9ce863 100644                                                                                                                                                                                                                                         
--- jubatus/core/bandit/ts.cpp                                                                                                                                                                                                                                        
+++ jubatus/core/bandit/ts.cpp                                                                                                                                                                                                                                        
@@ -53,8 +53,8 @@ std::string ts::select_arm(const std::string& player_id) {
       result = arms[i];                                                                                                                                                                                                                                              
     }                                                                                                                                                                                                                                                                
   }                                                                                                                                                                                                                                                                  
+  s_.notify_selected(player_id, result);                                                                                                                                                                                                                             
   return result;                                                                                                                                                                                                                                                     
-  //return arms[select_by_weights(weights, rand_)];                                                                                                                                                                                                                  
 }                                                                                                                                                                                                                                                                    
                                                                                                                                                                                                                                                                      
 bool ts::register_arm(const std::string& arm_id) {                                                                                                                                                                                                                   
@@ -64,12 +64,14 @@ bool ts::delete_arm(const std::string& arm_id) {
   return s_.delete_arm(arm_id);                                                                                                                                                                                                                                      
 }                                                                                                                                                                                                                                                                    
                                                                                                                                                                                                                                                                      
-bool ts::register_reward(const std::string& player_id,                                                                                                                                                                                                               
-                           const std::string& arm_id,                                                                                                                                                                                                                
-                           double reward) {                                                                                                                                                                                                                          
-  if( (reward != 0.0) && (reward != 1.0) ){                                                                                                                                                                                                                          
+bool ts::register_reward(                                                                                                                                                                                                                                            
+    const std::string& player_id,                                                                                                                                                                                                                                    
+    const std::string& arm_id,                                                                                                                                                                                                                                       
+    double reward) {                                                                                                                                                                                                                                                 
+  // Thompson sampling assumes binary rewards                                                                                                                                                                                                                        
+  if ((reward != 0.0) && (reward != 1.0)) {                                                                                                                                                                                                                          
     throw JUBATUS_EXCEPTION(                                                                                                                                                                                                                                         
-        common::exception::runtime_error("reward is not in {0,1}")); //Thompson sampling assumes binary rewards                                                                                                                                                      
+         common::exception::runtime_error("reward is not in {0,1}"));                                                                                                                                                                                                
   }                                                                                                                                                                                                                                                                  
   const std::vector<std::string>& arms = s_.get_arm_ids();                                                                                                                                                                                                           
   size_t i = std::find(arms.begin(), arms.end(), arm_id) - arms.begin();                                                                                                                                                                                             
diff --git jubatus/util/math/random.h jubatus/util/math/random.h                                                                                                                                                                                                      
index 5c54975..0f139c7 100644                                                                                                                                                                                                                                         
--- jubatus/util/math/random.h                                                                                                                                                                                                                                        
+++ jubatus/util/math/random.h                                                                                                                                                                                                                                        
@@ -134,7 +134,7 @@ public:
         }else{                                                                                                                                                                                                                                                       
           x = -log((1.0-u1)/(c*alpha));                                                                                                                                                                                                                              
           if( log(u2) <= (alpha-1)*log(x) ){                                                                                                                                                                                                                         
-            return true;                                                                                                                                                                                                                                             
+            return x;                                                                                                                                                                                                                                                
           }                                                                                                                                                                                                                                                          
         }                                                                                                                                                                                                                                                            
       }