# # Unity ML-Agents Toolkit import logging from typing import Dict, List, Deque, Any import os from mlagents.tf_utils import tf import numpy as np from collections import deque, defaultdict from mlagents.envs.exception import UnityException from mlagents.envs.timers import set_gauge from mlagents.trainers.trainer_metrics import TrainerMetrics from mlagents.trainers.tf_policy import TFPolicy from mlagents.trainers.trajectory import Trajectory from mlagents.trainers.brain import BrainParameters LOGGER = logging.getLogger("mlagents.trainers") class UnityTrainerException(UnityException): """ Related to errors with the Trainer. """ pass class Trainer(object): """This class is the base class for the mlagents.envs.trainers""" def __init__( self, brain: BrainParameters, trainer_parameters: dict, training: bool, run_id: str, reward_buff_cap: int = 1, ): """ Responsible for collecting experiences and training a neural network model. :BrainParameters brain: Brain to be trained. :dict trainer_parameters: The parameters for the trainer (dictionary). :bool training: Whether the trainer is set for training. :str run_id: The identifier of the current run :int reward_buff_cap: """ self.param_keys: List[str] = [] self.brain_name = brain.brain_name self.run_id = run_id self.trainer_parameters = trainer_parameters self.summary_path = trainer_parameters["summary_path"] if not os.path.exists(self.summary_path): os.makedirs(self.summary_path) self.cumulative_returns_since_policy_update: List[float] = [] self.is_training = training self.stats: Dict[str, List] = defaultdict(list) self.trainer_metrics = TrainerMetrics( path=self.summary_path + ".csv", brain_name=self.brain_name ) self.summary_writer = tf.summary.FileWriter(self.summary_path) self._reward_buffer: Deque[float] = deque(maxlen=reward_buff_cap) self.policy: TFPolicy = None # type: ignore # this will always get set self.step: int = 0 def check_param_keys(self): for k in self.param_keys: if k not in self.trainer_parameters: raise UnityTrainerException( "The hyper-parameter {0} could not be found for the {1} trainer of " "brain {2}.".format(k, self.__class__, self.brain_name) ) def dict_to_str(self, param_dict: Dict[str, Any], num_tabs: int) -> str: """ Takes a parameter dictionary and converts it to a human-readable string. Recurses if there are multiple levels of dict. Used to print out hyperaparameters. param: param_dict: A Dictionary of key, value parameters. return: A string version of this dictionary. """ if not isinstance(param_dict, dict): return str(param_dict) else: append_newline = "\n" if num_tabs > 0 else "" return append_newline + "\n".join( [ "\t" + " " * num_tabs + "{0}:\t{1}".format( x, self.dict_to_str(param_dict[x], num_tabs + 1) ) for x in param_dict ] ) def __str__(self) -> str: return """Hyperparameters for the {0} of brain {1}: \n{2}""".format( self.__class__.__name__, self.brain_name, self.dict_to_str(self.trainer_parameters, 0), ) @property def parameters(self) -> Dict[str, Any]: """ Returns the trainer parameters of the trainer. """ return self.trainer_parameters @property def get_max_steps(self) -> float: """ Returns the maximum number of steps. Is used to know when the trainer should be stopped. :return: The maximum number of steps of the trainer """ return float(self.trainer_parameters["max_steps"]) @property def get_step(self) -> int: """ Returns the number of steps the trainer has performed :return: the step count of the trainer """ return self.step @property def reward_buffer(self) -> Deque[float]: """ Returns the reward buffer. The reward buffer contains the cumulative rewards of the most recent episodes completed by agents using this trainer. :return: the reward buffer. """ return self._reward_buffer def increment_step(self, n_steps: int) -> None: """ Increment the step count of the trainer :param n_steps: number of steps to increment the step count by """ self.step = self.policy.increment_step(n_steps) def save_model(self) -> None: """ Saves the model """ self.policy.save_model(self.get_step) def export_model(self) -> None: """ Exports the model """ self.policy.export_model() def write_training_metrics(self) -> None: """ Write training metrics to a CSV file :return: """ self.trainer_metrics.write_training_metrics() def write_summary( self, global_step: int, delta_train_start: float, lesson_num: int = 0 ) -> None: """ Saves training statistics to Tensorboard. :param delta_train_start: Time elapsed since training started. :param lesson_num: Current lesson number in curriculum. :param global_step: The number of steps the simulation has been going for """ if ( global_step % self.trainer_parameters["summary_freq"] == 0 and global_step != 0 ): is_training = ( "Training." if self.is_training and self.get_step <= self.get_max_steps else "Not Training." ) step = min(self.get_step, self.get_max_steps) if len(self.stats["Environment/Cumulative Reward"]) > 0: mean_reward = np.mean(self.stats["Environment/Cumulative Reward"]) LOGGER.info( " {}: {}: Step: {}. " "Time Elapsed: {:0.3f} s " "Mean " "Reward: {:0.3f}" ". Std of Reward: {:0.3f}. {}".format( self.run_id, self.brain_name, step, delta_train_start, mean_reward, np.std(self.stats["Environment/Cumulative Reward"]), is_training, ) ) set_gauge(f"{self.brain_name}.mean_reward", mean_reward) else: LOGGER.info( " {}: {}: Step: {}. No episode was completed since last summary. {}".format( self.run_id, self.brain_name, step, is_training ) ) summary = tf.Summary() for key in self.stats: if len(self.stats[key]) > 0: stat_mean = float(np.mean(self.stats[key])) summary.value.add(tag="{}".format(key), simple_value=stat_mean) self.stats[key] = [] summary.value.add(tag="Environment/Lesson", simple_value=lesson_num) self.summary_writer.add_summary(summary, step) self.summary_writer.flush() def write_tensorboard_text(self, key: str, input_dict: Dict[str, Any]) -> None: """ Saves text to Tensorboard. Note: Only works on tensorflow r1.2 or above. :param key: The name of the text. :param input_dict: A dictionary that will be displayed in a table on Tensorboard. """ try: with tf.Session() as sess: s_op = tf.summary.text( key, tf.convert_to_tensor( ([[str(x), str(input_dict[x])] for x in input_dict]) ), ) s = sess.run(s_op) self.summary_writer.add_summary(s, self.get_step) except Exception: LOGGER.info( "Cannot write text summary for Tensorboard. Tensorflow version must be r1.2 or above." ) pass def process_trajectory(self, trajectory: Trajectory) -> None: """ Takes a trajectory and processes it, putting it into the update buffer. Processing involves calculating value and advantage targets for model updating step. :param trajectory: The Trajectory tuple containing the steps to be processed. """ raise UnityTrainerException( "The process_experiences method was not implemented." ) def end_episode(self): """ A signal that the Episode has ended. The buffer must be reset. Get only called when the academy resets. """ raise UnityTrainerException("The end_episode method was not implemented.") def is_ready_update(self): """ Returns whether or not the trainer has enough elements to run update model :return: A boolean corresponding to wether or not update_model() can be run """ raise UnityTrainerException("The is_ready_update method was not implemented.") def update_policy(self): """ Uses demonstration_buffer to update model. """ raise UnityTrainerException("The update_model method was not implemented.") def advance(self) -> None: pass