learnig: add ending and fix leak memory

deepQlearn_0/src/deepQlearning/learn_to_drive.c

@@ -90,6 +90,10 @@ struct status_qlearning * create_status_qlearning (){
   status_ql->list_target_cumul = create_var_list_TYPE_L_INT();
   status_ql->progress_best_cumul = create_var_list_TYPE_L_INT();
 
+	status_ql->ending = 0;
+	status_ql->mut_ending=malloc(sizeof(pthread_mutex_t));
+	pthread_mutex_init(status_ql->mut_ending, NULL);
+
   //push_back_list_TYPE_L_INT(status_ql->list_main_cumul, 0);
   //push_back_list_TYPE_L_INT(status_ql->list_target_cumul, 0);
   push_back_list_TYPE_L_INT(status_ql->progress_best_cumul, -10000);
@@ -192,6 +196,8 @@ void free_status_qlearning(struct status_qlearning *status_ql){
   free_all_var_list_TYPE_L_INT(status_ql->list_main_cumul);
   free_all_var_list_TYPE_L_INT(status_ql->list_target_cumul);
   free_all_var_list_TYPE_L_INT(status_ql->progress_best_cumul);
+	pthread_mutex_destroy(status_ql->mut_ending);
+	free(status_ql->mut_ending);
   free(status_ql);
 }
 void free_delay_params (struct delay_params *dly_p){
@@ -258,6 +264,7 @@ void train_qlearning(struct RL_agent * rlAgent,
 
 //  free_tensor_TYPE_FLOAT(action_value);
 //  free_tensor_TYPE_FLOAT(next_action_value);
+  free_tensor_TYPE_FLOAT(experimental_values);
 
 }
 
@@ -276,7 +283,7 @@ int select_action(struct RL_agent * rlAgent){
     //init =false;
   //}
   //int random = xrand() % randRange;
-  float proba_explor =  (float) (rand() % (1<<17 -1))/ (1<<17 -1); //frand(); //(float)(random ) / randRange;
+  float proba_explor =  (float) (xrand() % (1<<17 -1))/ (1<<17 -1); //frand(); //(float)(random ) / randRange;
   if(proba_explor > rlAgent->qlearnParams->exploration_factor ){
     action = ARG_MAX_ARRAY_TYPE_FLOAT( action_value->x, action_value->dim->rank  );
     //if(action == ARG_MIN_ARRAY_TYPE_FLOAT( action_value->x, action_value->dim->rank  )) 
@@ -307,13 +314,21 @@ int select_action(struct RL_agent * rlAgent){
   return action;
 }
 
+int is_ending(struct status_qlearning *qlStatus){
+	int ret;
+  pthread_mutex_lock(qlStatus->mut_ending);
+	ret = qlStatus->ending;
+  pthread_mutex_unlock(qlStatus->mut_ending);
+	return ret;
+}
+
 void* runPrint(void *arg){
   struct RL_agent *rlAgent = (struct RL_agent*)arg;
   struct status_qlearning *qlStatus = rlAgent->status;
   struct print_params * pprint = rlAgent->pprint;
   struct vehicle *car = rlAgent->car;
   size_t count_print = 0;
-  while(1){
+  while(!is_ending(qlStatus)){
 if(/*(qlStatus->nb_episodes %125 == 0)  &&*/  pprint->printed){
           //pthread_mutex_lock(&(pprint->mut_printed));
           pthread_mutex_lock(&(car->mut_coord));
@@ -350,6 +365,7 @@ if(/*(qlStatus->nb_episodes %125 == 0)  &&*/  pprint->printed){
             clear_screen();
           }
   }
+	return NULL;
 }
 
 char *fileNameDateScore(char * pre, char* post,size_t score){
@@ -375,7 +391,7 @@ void learn_to_drive(struct RL_agent * rlAgent){
   pthread_t threadPrint;
   pthread_create(&threadPrint, NULL, runPrint, (void*)rlAgent);
   
-  while(true){
+ // while(true){
     for(size_t index_episode = 0; index_episode < qlParams->number_episodes; ++index_episode){
       reset(car);
       qlStatus->nb_training_after_updated_weight_in_target = 0;
@@ -414,7 +430,10 @@ void learn_to_drive(struct RL_agent * rlAgent){
       //  Sleep(pprint->delay->delay_between_episodes);
       //}
     }
-  }
+			pthread_mutex_lock(qlStatus->mut_ending);
+			qlStatus->ending = 1;
+			pthread_mutex_unlock(qlStatus->mut_ending);
+//  }
 
   pthread_join(threadPrint, NULL);
 }

deepQlearn_0/src/deepQlearning/learn_to_drive.h

@@ -50,7 +50,8 @@ struct status_qlearning {
   size_t nb_episodes;
   size_t index_episode;
   int action;
-//  int last_action;
+  int ending;
+	pthread_mutex_t *mut_ending;
 //  size_t count_last_action;
 };
 

deepQlearn_0/test/Makefile

@@ -29,7 +29,7 @@ TEST_DIR=$(PWD)
 EXECSRC=$(NAME_TEST).c 
 #EXECSRC=openF.c
 
-EXEC=launch_$(NAME_TEST)_m
+EXEC=l1aunch_$(NAME_TEST)_m
 
 NEUROSRC=$(NEURODIR)/src/neuron_t/neuron_t.c
 NEUROSRC_O=$(NEUROSRC:.c=.o)

deepQlearn_0/test/is_good.c

@@ -511,7 +511,7 @@ scanf("%c",&c);
 }
 #endif
 
-
+// **************************************************************
 
 #if 1
 TEST(first_learn_vehicle_50__9){
@@ -633,20 +633,20 @@ EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->main_net, weigh
 EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->target_net, weight_in, ".ff_target_20240717_01h42m16s_5300.txt");
 */
 
-EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->main_net, weight_in, ".ff_main_20240717_09h11m09s_1700.txt");
+//EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->main_net, weight_in, ".ff_main_20240717_09h11m09s_1700.txt");
-EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->target_net, weight_in, ".ff_target_20240717_09h11m09s_1700.txt");
+//EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->target_net, weight_in, ".ff_target_20240717_09h11m09s_1700.txt");
 
 struct status_qlearning *qlstatus = create_status_qlearning ();
   struct delay_params *dly = create_delay_params (
-    500/*size_t delay_between_episodes*/,
+    50000  /*size_t delay_between_episodes*/,
-    50/*size_t delay_between_games*/
+    500/*size_t delay_between_games*/
   );
   
   struct qlearning_params *qlparams = create_qlearning_params (
     0.95/*float gamma*/,
     learning_rate,
     0 /* (not used!)float discount_factor*/,
-    0.0001/*0.99*/  /*float exploration_factor*/,
+    0.01/*0.99*/  /*float exploration_factor*/,
     20/*long int nb_training_before_update_weight_in_target*/,
     10000/*size_t number_episodes*/
   );
@@ -681,12 +681,184 @@ struct status_qlearning *qlstatus = create_status_qlearning ();
 
 
 
+// ****************************************************************
+
 #if 1
 TEST(first_learn_vehicle_50__10){
   size_t nb_block = 7;
   size_t dim= 2;
   struct blocks * path = create_blocks(nb_block, dim);
 
+#if 1
+    copy_coordinate(path->lower_bound_block[0], (float[]){0,0});
+  copy_coordinate(path->upper_bound_block[0], (float[]){150,250});
+  copy_coordinate(path->lower_bound_block[1], (float[]){150,0});
+  copy_coordinate(path->upper_bound_block[1], (float[]){250,150});
+  copy_coordinate(path->lower_bound_block[2], (float[]){250,80});
+  copy_coordinate(path->upper_bound_block[2], (float[]){360,200});
+  copy_coordinate(path->lower_bound_block[3], (float[]){360,70});
+  copy_coordinate(path->upper_bound_block[3], (float[]){600,170});
+  copy_coordinate(path->lower_bound_block[4], (float[]){600,90});
+  copy_coordinate(path->upper_bound_block[4], (float[]){760,300});
+  copy_coordinate(path->lower_bound_block[5], (float[]){300,300});
+  copy_coordinate(path->upper_bound_block[5], (float[]){760,350});
+  copy_coordinate(path->lower_bound_block[6], (float[]){0,250});
+  copy_coordinate(path->upper_bound_block[6], (float[]){410,300});
+
+
+
+/*
+
+  copy_coordinate(path->lower_bound_block[4], (float[]){0,0});
+  copy_coordinate(path->upper_bound_block[4], (float[]){150,250});
+  copy_coordinate(path->lower_bound_block[3], (float[]){150,40});
+  copy_coordinate(path->upper_bound_block[3], (float[]){250,150});
+  copy_coordinate(path->lower_bound_block[2], (float[]){250,80});
+  copy_coordinate(path->upper_bound_block[2], (float[]){360,200});
+  copy_coordinate(path->lower_bound_block[1], (float[]){360,70});
+  copy_coordinate(path->upper_bound_block[1], (float[]){600,150});
+  copy_coordinate(path->lower_bound_block[0], (float[]){600,90});
+  copy_coordinate(path->upper_bound_block[0], (float[]){760,300});
+  copy_coordinate(path->lower_bound_block[6], (float[]){260,300});
+  copy_coordinate(path->upper_bound_block[6], (float[]){760,360});
+  copy_coordinate(path->lower_bound_block[5], (float[]){0,250});
+  copy_coordinate(path->upper_bound_block[5], (float[]){410,300});
+
+
+  copy_coordinate(path->lower_bound_block[0], (float[]){0,0});
+  copy_coordinate(path->upper_bound_block[0], (float[]){100,250});
+  copy_coordinate(path->lower_bound_block[1], (float[]){100,0});
+  copy_coordinate(path->upper_bound_block[1], (float[]){250,80});
+  copy_coordinate(path->lower_bound_block[2], (float[]){250,0});
+  copy_coordinate(path->upper_bound_block[2], (float[]){360,140});
+  copy_coordinate(path->lower_bound_block[3], (float[]){360,70});
+  copy_coordinate(path->upper_bound_block[3], (float[]){600,140});
+  copy_coordinate(path->lower_bound_block[4], (float[]){600,90});
+  copy_coordinate(path->upper_bound_block[4], (float[]){720,300});
+  copy_coordinate(path->lower_bound_block[5], (float[]){300,300});
+  copy_coordinate(path->upper_bound_block[5], (float[]){720,350});
+  copy_coordinate(path->lower_bound_block[6], (float[]){0,250});
+  copy_coordinate(path->upper_bound_block[6], (float[]){410,300});
+ 
+
+
+
+  copy_coordinate(path->lower_bound_block[0], (float[]){0,300});
+  copy_coordinate(path->upper_bound_block[0], (float[]){400,700});
+  copy_coordinate(path->lower_bound_block[1], (float[]){100,0});
+  copy_coordinate(path->upper_bound_block[1], (float[]){1000,300});
+  copy_coordinate(path->lower_bound_block[2], (float[]){1000,50});
+  copy_coordinate(path->upper_bound_block[2], (float[]){1400,500});
+  copy_coordinate(path->lower_bound_block[3], (float[]){1400,200});
+  copy_coordinate(path->upper_bound_block[3], (float[]){1800,700});
+  copy_coordinate(path->lower_bound_block[4], (float[]){1100,700});
+  copy_coordinate(path->upper_bound_block[4], (float[]){1700,1000});
+  copy_coordinate(path->lower_bound_block[5], (float[]){800,600});
+  copy_coordinate(path->upper_bound_block[5], (float[]){1100,975});
+  copy_coordinate(path->lower_bound_block[6], (float[]){100,700});
+  copy_coordinate(path->upper_bound_block[6], (float[]){800,975});
+ */
+
+#else 
+
+  copy_coordinate(path->lower_bound_block[0], (float[]){0,3});
+  copy_coordinate(path->upper_bound_block[0], (float[]){4,7});
+  copy_coordinate(path->lower_bound_block[1], (float[]){1,0});
+  copy_coordinate(path->upper_bound_block[1], (float[]){10,3});
+  copy_coordinate(path->lower_bound_block[2], (float[]){10,0.5});
+  copy_coordinate(path->upper_bound_block[2], (float[]){14,5});
+  copy_coordinate(path->lower_bound_block[3], (float[]){14,2});
+  copy_coordinate(path->upper_bound_block[3], (float[]){18,7});
+  copy_coordinate(path->lower_bound_block[4], (float[]){11,7});
+  copy_coordinate(path->upper_bound_block[4], (float[]){17,10});
+  copy_coordinate(path->lower_bound_block[5], (float[]){8,6});
+  copy_coordinate(path->upper_bound_block[5], (float[]){11,9.75});
+  copy_coordinate(path->lower_bound_block[6], (float[]){1,7});
+  copy_coordinate(path->upper_bound_block[6], (float[]){8,9.75});
+ 
+ 
+#endif
+
+  update_bounds_limits_blocks(path);
+
+  struct vehicle *car = create_vehicle(path);
+
+  config_layers *pconf = create_config_layers_from_OneD(4,(size_t[]){3,24,24,3}); /* 3 input , 3 target; 2 hidden layer with 24 neurons each */
+  //config_layers *pconf = create_config_layers_from_OneD(4,(size_t[]){3,14,14,3}); /* 3 input , 3 target; 2 hidden layer with 24 neurons each */
+  
+  bool randomize=true; 
+  float minR = -0.5, maxR = 0.5;  
+  int randomRange = 500;
+  size_t nb_prod_thread = 2;
+  size_t nb_calc_thread = 4;
+  float learning_rate = 0.00001 /* 0.001*/;  
+  struct networks_qlearning *nnetworks = create_nework_qlearning(
+    pconf,
+    randomize, minR, maxR,  randomRange,
+    nb_prod_thread, nb_calc_thread,
+    learning_rate
+  );
+/*
+EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->main_net, weight_in, ".ff_main_20240717_01h42m16s_5300.txt");
+EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->target_net, weight_in, ".ff_target_20240717_01h42m16s_5300.txt");
+*/
+
+/*
+EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->main_net, weight_in, ".ff_main_20240717_09h11m09s_1700.txt");
+EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->target_net, weight_in, ".ff_target_20240717_09h11m09s_1700.txt");
+*/
+
+struct status_qlearning *qlstatus = create_status_qlearning ();
+  struct delay_params *dly = create_delay_params (
+    500/*size_t delay_between_episodes*/,
+    50/*size_t delay_between_games*/
+  );
+  
+  struct qlearning_params *qlparams = create_qlearning_params (
+    0.95/*float gamma*/,
+    learning_rate,
+    0 /* (not used!)float discount_factor*/,
+    0.0001/*0.99*/  /*float exploration_factor*/,
+20/*long int nb_training_before_update_weight_in_target*/,
+1 /*size_t number_episodes*/
+  );
+/*   UPDATE_ATTRIBUTE_NEURONE_IN_ALL_LAYERS(TYPE_FLOAT, nnetworks->main_net, d_f_act , df );
+   UPDATE_ATTRIBUTE_NEURONE_IN_ALL_LAYERS(TYPE_FLOAT, nnetworks->main_net, f_act, f );
+   UPDATE_ATTRIBUTE_NEURONE_IN_ALL_LAYERS(TYPE_FLOAT, nnetworks->target_net, d_f_act , df );
+   UPDATE_ATTRIBUTE_NEURONE_IN_ALL_LAYERS(TYPE_FLOAT, nnetworks->target_net, f_act , f );
+*/
+  struct print_params *pprint = create_print_params(
+    12/*float scale_x*/,12 /*float scale_y*/,  
+    dly/*struct delay_params * dly_p*/
+);
+
+  struct RL_agent *rlAgent = create_RL_agent (
+    nnetworks /*struct networks_qlearning * networks*/,
+    car /*struct vehicle *  car*/,
+    qlstatus /*struct status_qlearning * status*/,
+    pprint /*struct print_params * pprint*/,
+    qlparams/*struct qlearning_params *qlearnParams*/
+  );
+
+
+  learn_to_drive(rlAgent);
+
+  free_RL_agent(rlAgent);
+
+
+
+
+}
+#endif
+
+
+
+#if 1
+TEST(first_learn_vehicle_50__11){
+  size_t nb_block = 7;
+  size_t dim= 2;
+  struct blocks * path = create_blocks(nb_block, dim);
+
 #if 1
 
   copy_coordinate(path->lower_bound_block[0], (float[]){0,0});
@@ -791,7 +963,7 @@ copy_coordinate(path->lower_bound_block[0], (float[]){0,0});
   int randomRange = 500;
   size_t nb_prod_thread = 2;
   size_t nb_calc_thread = 4;
-  float learning_rate = 0.00001 /* 0.001*/;  
+  float learning_rate = 0; /* 0.000001*/ /* 0.001*/;  
   struct networks_qlearning *nnetworks = create_nework_qlearning(
     pconf,
     randomize, minR, maxR,  randomRange,
@@ -803,9 +975,12 @@ EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->main_net, weigh
 EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->target_net, weight_in, ".ff_target_20240717_01h42m16s_5300.txt");
 */
 
-EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->main_net, weight_in, ".ff_main_20240717_09h11m09s_1700.txt");
+EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->main_net, weight_in, ".ff_main_20250508_17h50m56s_26300.txt");
-EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->target_net, weight_in, ".ff_target_20240717_09h11m09s_1700.txt");
+EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->target_net, weight_in, ".ff_target_20250508_17h50m56s_26300.txt");
-
+/*
+EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->main_net, weight_in, ".ff_main_20250508_23h02m40s_29000.txt");
+EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->target_net, weight_in, ".ff_target_20250508_23h02m40s_29000.txt");
+*/
 struct status_qlearning *qlstatus = create_status_qlearning ();
   struct delay_params *dly = create_delay_params (
     500/*size_t delay_between_episodes*/,
@@ -852,7 +1027,7 @@ struct status_qlearning *qlstatus = create_status_qlearning ();
 
 
 #if 1
-TEST(first_learn_vehicle_50__11){
+TEST(first_learn_vehicle_50__12){
   size_t nb_block = 10;
   size_t dim= 2;
   struct blocks * path = create_blocks(nb_block, dim);
@@ -967,7 +1142,7 @@ copy_coordinate(path->lower_bound_block[0], (float[]){0,0});
   int randomRange = 500;
   size_t nb_prod_thread = 2;
   size_t nb_calc_thread = 4;
-  float learning_rate = 0.00001 /* 0.001*/;  
+  float learning_rate = 0.0000001 /* 0.001*/;  
   struct networks_qlearning *nnetworks = create_nework_qlearning(
     pconf,
     randomize, minR, maxR,  randomRange,
@@ -976,9 +1151,12 @@ copy_coordinate(path->lower_bound_block[0], (float[]){0,0});
   );
 
 //print_vehicle_n_path(car, 12, 12);
-
+/*
 EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->main_net, weight_in, ".ff_main_20240717_09h11m09s_1700.txt");
 EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->target_net, weight_in, ".ff_target_20240717_09h11m09s_1700.txt");
+*/
+EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->main_net, weight_in, ".ff_main_20250508_17h50m56s_26300.txt");
+EXTRACT_FILE_TO_TENSOR_ATTRIBUTE_NNEURONS(TYPE_FLOAT, nnetworks->target_net, weight_in, ".ff_target_20250508_17h50m56s_26300.txt");
 
 struct status_qlearning *qlstatus = create_status_qlearning ();
   struct delay_params *dly = create_delay_params (
@@ -990,9 +1168,9 @@ struct status_qlearning *qlstatus = create_status_qlearning ();
     0.95/*float gamma*/,
     learning_rate,
     0 /* (not used!)float discount_factor*/,
-    0.0001/*0.99*/  /*float exploration_factor*/,
+    0.1/*0.99*/  /*float exploration_factor*/,
     20/*long int nb_training_before_update_weight_in_target*/,
-    10000/*size_t number_episodes*/
+    1/*size_t number_episodes*/
   );
 /*   UPDATE_ATTRIBUTE_NEURONE_IN_ALL_LAYERS(TYPE_FLOAT, nnetworks->main_net, d_f_act , df );
    UPDATE_ATTRIBUTE_NEURONE_IN_ALL_LAYERS(TYPE_FLOAT, nnetworks->main_net, f_act, f );
@@ -1029,7 +1207,7 @@ struct status_qlearning *qlstatus = create_status_qlearning ();
 
 
 #if 1
-TEST(first_learn_vehicle){
+TEST(first_learn_vehicle13){
   size_t nb_block = 7;
   size_t dim= 2;
   struct blocks * path = create_blocks(nb_block, dim);

neuron_t/src/neuron_t/neuron_t.c

@@ -635,7 +635,7 @@ void print_weight_in_neurons_##type(neurons_##type *nn, char *msg){\
     if(tmp->weight_in){\
       sprintf(vmsg,"%s layer %ld",msg,i++);\
       print_tensor_msg_##type(tmp->weight_in, vmsg);\
-    }else{printf("weight_in %d NULL\n",i);}\
+    }else{printf("weight_in %ld NULL\n",i);}\
     tmp = tmp->next_layer;\
   }\
 }\

qlearn_0/src/Frozen_Lake.c

@@ -330,7 +330,7 @@ void mainQlearning_game(struct game *gm){
 
         print_game_dim2(gm);
      		
-			 	//getchar();	
+			 //	getchar();	
         usleep((gm->delay)->delay_between_episodes);
         
       }

qlearn_0/test/is_good.c

@@ -6,9 +6,9 @@
 
 
 TEST(igameRabbit ){
-  size_t array[] = {6,6} ;
+  size_t array[] = {4,4} ;
   dimension *dim = init_copy_dim(array,2);
-  struct game_params * params = create_game_params(4,dim,3,3,1,200,200);
+  struct game_params * params = create_game_params(1,dim,3,3,1,200,200);
   struct qlearning_params * qlearnParams = create_qlearning_params(0.85,0.99,1);
   struct delay_params * delay_game = create_delay_params(100000, 20000);
   struct game * gm = create_game(params, qlearnParams, delay_game);

ytools_t/src/tools_t/tools_t.c

@@ -24,9 +24,12 @@ int xrand(){
   static bool init = true;
   if(init){
     init = false;
-    struct timespec start_t;
+		srand(time(NULL));
+    /*
+		struct timespec start_t;
     clock_gettime(CLOCK_REALTIME, &start_t);
     srand(start_t.tv_nsec);
+		*/
       //srand(start_t.tv_nsec - start_t.tv_sec);
   }
   int ret = rand ();