import logging from typing import Any, Dict, List, Optional import numpy as np from mlagents.tf_utils import tf from mlagents import tf_utils from mlagents_envs.exception import UnityException from mlagents.trainers.policy import Policy from mlagents.trainers.action_info import ActionInfo from tensorflow.python.platform import gfile from tensorflow.python.framework import graph_util from mlagents.trainers import tensorflow_to_barracuda as tf2bc from mlagents.trainers.trajectory import SplitObservations from mlagents.trainers.buffer import AgentBuffer from mlagents.trainers.brain_conversion_utils import get_global_agent_id from mlagents_envs.base_env import BatchedStepResult logger = logging.getLogger("mlagents.trainers") class UnityPolicyException(UnityException): """ Related to errors with the Trainer. """ pass class TFPolicy(Policy): """ Contains a learning model, and the necessary functions to interact with it to perform evaluate and updating. """ possible_output_nodes = [ "action", "value_estimate", "action_probs", "recurrent_out", "memory_size", "version_number", "is_continuous_control", "action_output_shape", ] def __init__(self, seed, brain, trainer_parameters): """ Initialized the policy. :param seed: Random seed to use for TensorFlow. :param brain: The corresponding Brain for this policy. :param trainer_parameters: The trainer parameters. """ # for ghost trainer save/load snapshots self.assign_phs = [] self.assign_ops = [] self.m_size = None self.model = None self.inference_dict = {} self.update_dict = {} self.sequence_length = 1 self.seed = seed self.brain = brain self.use_recurrent = trainer_parameters["use_recurrent"] self.memory_dict: Dict[str, np.ndarray] = {} self.reward_signals: Dict[str, "RewardSignal"] = {} self.num_branches = len(self.brain.vector_action_space_size) self.previous_action_dict: Dict[str, np.array] = {} self.normalize = trainer_parameters.get("normalize", False) self.use_continuous_act = brain.vector_action_space_type == "continuous" if self.use_continuous_act: self.num_branches = self.brain.vector_action_space_size[0] self.model_path = trainer_parameters["model_path"] self.keep_checkpoints = trainer_parameters.get("keep_checkpoints", 5) self.graph = tf.Graph() self.sess = tf.Session( config=tf_utils.generate_session_config(), graph=self.graph ) self.saver = None if self.use_recurrent: self.m_size = trainer_parameters["memory_size"] self.sequence_length = trainer_parameters["sequence_length"] if self.m_size == 0: raise UnityPolicyException( "The memory size for brain {0} is 0 even " "though the trainer uses recurrent.".format(brain.brain_name) ) elif self.m_size % 4 != 0: raise UnityPolicyException( "The memory size for brain {0} is {1} " "but it must be divisible by 4.".format( brain.brain_name, self.m_size ) ) def _initialize_graph(self): with self.graph.as_default(): self.saver = tf.train.Saver(max_to_keep=self.keep_checkpoints) init = tf.global_variables_initializer() self.sess.run(init) def _load_graph(self): with self.graph.as_default(): self.saver = tf.train.Saver(max_to_keep=self.keep_checkpoints) logger.info("Loading Model for brain {}".format(self.brain.brain_name)) ckpt = tf.train.get_checkpoint_state(self.model_path) if ckpt is None: logger.info( "The model {0} could not be found. Make " "sure you specified the right " "--run-id".format(self.model_path) ) self.saver.restore(self.sess, ckpt.model_checkpoint_path) def get_weights(self): with self.graph.as_default(): _vars = tf.get_collection(tf.GraphKeys.GLOBAL_VARIABLES) values = [v.eval(session=self.sess) for v in _vars] return values def init_load_weights(self): with self.graph.as_default(): _vars = tf.get_collection(tf.GraphKeys.GLOBAL_VARIABLES) values = [v.eval(session=self.sess) for v in _vars] for var, value in zip(_vars, values): assign_ph = tf.placeholder(var.dtype, shape=value.shape) self.assign_phs.append(assign_ph) self.assign_ops.append(tf.assign(var, assign_ph)) def load_weights(self, values): with self.graph.as_default(): feed_dict = {} for assign_ph, value in zip(self.assign_phs, values): feed_dict[assign_ph] = value self.sess.run(self.assign_ops, feed_dict=feed_dict) def evaluate( self, batched_step_result: BatchedStepResult, global_agent_ids: List[str] ) -> Dict[str, Any]: """ Evaluates policy for the agent experiences provided. :param batched_step_result: BatchedStepResult input to network. :return: Output from policy based on self.inference_dict. """ raise UnityPolicyException("The evaluate function was not implemented.") def get_action( self, batched_step_result: BatchedStepResult, worker_id: int = 0 ) -> ActionInfo: """ Decides actions given observations information, and takes them in environment. :param batched_step_result: A dictionary of brain names and BatchedStepResult from environment. :param worker_id: In parallel environment training, the unique id of the environment worker that the BatchedStepResult came from. Used to construct a globally unique id for each agent. :return: an ActionInfo containing action, memories, values and an object to be passed to add experiences """ if batched_step_result.n_agents() == 0: return ActionInfo.empty() agents_done = [ agent for agent, done in zip( batched_step_result.agent_id, batched_step_result.done ) if done ] self.remove_memories(agents_done) self.remove_previous_action(agents_done) global_agent_ids = [ get_global_agent_id(worker_id, int(agent_id)) for agent_id in batched_step_result.agent_id ] # For 1-D array, the iterator order is correct. run_out = self.evaluate( # pylint: disable=assignment-from-no-return batched_step_result, global_agent_ids ) self.save_memories(global_agent_ids, run_out.get("memory_out")) return ActionInfo( action=run_out.get("action"), value=run_out.get("value"), outputs=run_out, agent_ids=batched_step_result.agent_id, ) def update(self, mini_batch, num_sequences): """ Performs update of the policy. :param num_sequences: Number of experience trajectories in batch. :param mini_batch: Batch of experiences. :return: Results of update. """ raise UnityPolicyException("The update function was not implemented.") def _execute_model(self, feed_dict, out_dict): """ Executes model. :param feed_dict: Input dictionary mapping nodes to input data. :param out_dict: Output dictionary mapping names to nodes. :return: Dictionary mapping names to input data. """ network_out = self.sess.run(list(out_dict.values()), feed_dict=feed_dict) run_out = dict(zip(list(out_dict.keys()), network_out)) return run_out def fill_eval_dict(self, feed_dict, batched_step_result): vec_vis_obs = SplitObservations.from_observations(batched_step_result.obs) for i, _ in enumerate(vec_vis_obs.visual_observations): feed_dict[self.model.visual_in[i]] = vec_vis_obs.visual_observations[i] if self.use_vec_obs: feed_dict[self.model.vector_in] = vec_vis_obs.vector_observations if not self.use_continuous_act: mask = np.ones( ( batched_step_result.n_agents(), np.sum(self.brain.vector_action_space_size), ), dtype=np.float32, ) if batched_step_result.action_mask is not None: mask = 1 - np.concatenate(batched_step_result.action_mask, axis=1) feed_dict[self.model.action_masks] = mask return feed_dict def make_empty_memory(self, num_agents): """ Creates empty memory for use with RNNs :param num_agents: Number of agents. :return: Numpy array of zeros. """ return np.zeros((num_agents, self.m_size), dtype=np.float32) def save_memories( self, agent_ids: List[str], memory_matrix: Optional[np.ndarray] ) -> None: if memory_matrix is None: return for index, agent_id in enumerate(agent_ids): self.memory_dict[agent_id] = memory_matrix[index, :] def retrieve_memories(self, agent_ids: List[str]) -> np.ndarray: memory_matrix = np.zeros((len(agent_ids), self.m_size), dtype=np.float32) for index, agent_id in enumerate(agent_ids): if agent_id in self.memory_dict: memory_matrix[index, :] = self.memory_dict[agent_id] return memory_matrix def remove_memories(self, agent_ids): for agent_id in agent_ids: if agent_id in self.memory_dict: self.memory_dict.pop(agent_id) def make_empty_previous_action(self, num_agents): """ Creates empty previous action for use with RNNs and discrete control :param num_agents: Number of agents. :return: Numpy array of zeros. """ return np.zeros((num_agents, self.num_branches), dtype=np.int) def save_previous_action( self, agent_ids: List[str], action_matrix: Optional[np.ndarray] ) -> None: if action_matrix is None: return for index, agent_id in enumerate(agent_ids): self.previous_action_dict[agent_id] = action_matrix[index, :] def retrieve_previous_action(self, agent_ids: List[str]) -> np.ndarray: action_matrix = np.zeros((len(agent_ids), self.num_branches), dtype=np.int) for index, agent_id in enumerate(agent_ids): if agent_id in self.previous_action_dict: action_matrix[index, :] = self.previous_action_dict[agent_id] return action_matrix def remove_previous_action(self, agent_ids): for agent_id in agent_ids: if agent_id in self.previous_action_dict: self.previous_action_dict.pop(agent_id) def get_current_step(self): """ Gets current model step. :return: current model step. """ step = self.sess.run(self.model.global_step) return step def increment_step(self, n_steps): """ Increments model step. """ out_dict = { "global_step": self.model.global_step, "increment_step": self.model.increment_step, } feed_dict = {self.model.steps_to_increment: n_steps} return self.sess.run(out_dict, feed_dict=feed_dict)["global_step"] def get_inference_vars(self): """ :return:list of inference var names """ return list(self.inference_dict.keys()) def get_update_vars(self): """ :return:list of update var names """ return list(self.update_dict.keys()) def save_model(self, steps): """ Saves the model :param steps: The number of steps the model was trained for :return: """ with self.graph.as_default(): last_checkpoint = self.model_path + "/model-" + str(steps) + ".cptk" self.saver.save(self.sess, last_checkpoint) tf.train.write_graph( self.graph, self.model_path, "raw_graph_def.pb", as_text=False ) def export_model(self): """ Exports latest saved model to .nn format for Unity embedding. """ with self.graph.as_default(): target_nodes = ",".join(self._process_graph()) graph_def = self.graph.as_graph_def() output_graph_def = graph_util.convert_variables_to_constants( self.sess, graph_def, target_nodes.replace(" ", "").split(",") ) frozen_graph_def_path = self.model_path + "/frozen_graph_def.pb" with gfile.GFile(frozen_graph_def_path, "wb") as f: f.write(output_graph_def.SerializeToString()) tf2bc.convert(frozen_graph_def_path, self.model_path + ".nn") logger.info("Exported " + self.model_path + ".nn file") def _process_graph(self): """ Gets the list of the output nodes present in the graph for inference :return: list of node names """ all_nodes = [x.name for x in self.graph.as_graph_def().node] nodes = [x for x in all_nodes if x in self.possible_output_nodes] logger.info("List of nodes to export for brain :" + self.brain.brain_name) for n in nodes: logger.info("\t" + n) return nodes def update_normalization(self, vector_obs: np.ndarray) -> None: """ If this policy normalizes vector observations, this will update the norm values in the graph. :param vector_obs: The vector observations to add to the running estimate of the distribution. """ if self.use_vec_obs and self.normalize: self.sess.run( self.model.update_normalization, feed_dict={self.model.vector_in: vector_obs}, ) def get_batched_value_estimates(self, batch: AgentBuffer) -> Dict[str, np.ndarray]: feed_dict: Dict[tf.Tensor, Any] = { self.model.batch_size: batch.num_experiences, self.model.sequence_length: 1, # We want to feed data in batch-wise, not time-wise. } if self.use_vec_obs: feed_dict[self.model.vector_in] = batch["vector_obs"] if self.model.vis_obs_size > 0: for i in range(len(self.model.visual_in)): _obs = batch["visual_obs%d" % i] feed_dict[self.model.visual_in[i]] = _obs if self.use_recurrent: feed_dict[self.model.memory_in] = batch["memory"] if not self.use_continuous_act and self.use_recurrent: feed_dict[self.model.prev_action] = batch["prev_action"] value_estimates = self.sess.run(self.model.value_heads, feed_dict) value_estimates = {k: np.squeeze(v, axis=1) for k, v in value_estimates.items()} return value_estimates def get_value_estimates( self, next_obs: List[np.ndarray], agent_id: str, done: bool ) -> Dict[str, float]: """ Generates value estimates for bootstrapping. :param experience: AgentExperience to be used for bootstrapping. :param done: Whether or not this is the last element of the episode, in which case the value estimate will be 0. :return: The value estimate dictionary with key being the name of the reward signal and the value the corresponding value estimate. """ feed_dict: Dict[tf.Tensor, Any] = { self.model.batch_size: 1, self.model.sequence_length: 1, } vec_vis_obs = SplitObservations.from_observations(next_obs) for i in range(len(vec_vis_obs.visual_observations)): feed_dict[self.model.visual_in[i]] = [vec_vis_obs.visual_observations[i]] if self.use_vec_obs: feed_dict[self.model.vector_in] = [vec_vis_obs.vector_observations] if self.use_recurrent: feed_dict[self.model.memory_in] = self.retrieve_memories([agent_id]) if not self.use_continuous_act and self.use_recurrent: feed_dict[self.model.prev_action] = self.retrieve_previous_action( [agent_id] ) value_estimates = self.sess.run(self.model.value_heads, feed_dict) value_estimates = {k: float(v) for k, v in value_estimates.items()} # If we're done, reassign all of the value estimates that need terminal states. if done: for k in value_estimates: if self.reward_signals[k].use_terminal_states: value_estimates[k] = 0.0 return value_estimates @property def vis_obs_size(self): return self.model.vis_obs_size @property def vec_obs_size(self): return self.model.vec_obs_size @property def use_vis_obs(self): return self.model.vis_obs_size > 0 @property def use_vec_obs(self): return self.model.vec_obs_size > 0