from gym import Env from gym.spaces import Box import numpy as np import re import unittest import ray.rllib.agents.sac as sac from ray.rllib.agents.sac.sac_torch_policy import actor_critic_loss as \ loss_torch from ray.rllib.models.tf.tf_action_dist import SquashedGaussian from ray.rllib.models.torch.torch_action_dist import TorchSquashedGaussian from ray.rllib.policy.sample_batch import SampleBatch from ray.rllib.utils.framework import try_import_tf, try_import_torch from ray.rllib.utils.numpy import fc, relu from ray.rllib.utils.test_utils import check, framework_iterator from ray.rllib.utils.torch_ops import convert_to_torch_tensor tf = try_import_tf() torch, _ = try_import_torch() class SimpleEnv(Env): def __init__(self, config): self.action_space = Box(0.0, 1.0, (1, )) self.observation_space = Box(0.0, 1.0, (1, )) self.max_steps = config.get("max_steps", 100) self.state = None self.steps = None def reset(self): self.state = self.observation_space.sample() self.steps = 0 return self.state def step(self, action): self.steps += 1 # Reward is 1.0 - (action - state). [r] = 1.0 - np.abs(action - self.state) d = self.steps >= self.max_steps self.state = self.observation_space.sample() return self.state, r, d, {} class TestSAC(unittest.TestCase): def test_sac_compilation(self): """Tests whether an SACTrainer can be built with all frameworks.""" config = sac.DEFAULT_CONFIG.copy() config["num_workers"] = 0 # Run locally. config["twin_q"] = True config["soft_horizon"] = True config["clip_actions"] = False config["normalize_actions"] = True config["learning_starts"] = 0 config["prioritized_replay"] = True num_iterations = 1 for _ in framework_iterator(config, ("tf", "torch")): # Test for different env types (discrete w/ and w/o image, + cont). for env in [ "Pendulum-v0", "MsPacmanNoFrameskip-v4", "CartPole-v0" ]: print("Env={}".format(env)) config["use_state_preprocessor"] = \ env == "MsPacmanNoFrameskip-v4" trainer = sac.SACTrainer(config=config, env=env) for i in range(num_iterations): results = trainer.train() print(results) def test_sac_loss_function(self): """Tests SAC function results across all frameworks.""" config = sac.DEFAULT_CONFIG.copy() # Run locally. config["num_workers"] = 0 config["learning_starts"] = 0 config["twin_q"] = False config["gamma"] = 0.99 # Switch on deterministic loss so we can compare the loss values. config["_deterministic_loss"] = True # Use very simple nets. config["Q_model"]["fcnet_hiddens"] = [10] config["policy_model"]["fcnet_hiddens"] = [10] # Make sure, timing differences do not affect trainer.train(). config["min_iter_time_s"] = 0 map_ = { # Normal net. "default_policy/sequential/action_1/kernel": "action_model." "action_0._model.0.weight", "default_policy/sequential/action_1/bias": "action_model." "action_0._model.0.bias", "default_policy/sequential/action_out/kernel": "action_model." "action_out._model.0.weight", "default_policy/sequential/action_out/bias": "action_model." "action_out._model.0.bias", "default_policy/sequential_1/q_hidden_0/kernel": "q_net." "q_hidden_0._model.0.weight", "default_policy/sequential_1/q_hidden_0/bias": "q_net." "q_hidden_0._model.0.bias", "default_policy/sequential_1/q_out/kernel": "q_net." "q_out._model.0.weight", "default_policy/sequential_1/q_out/bias": "q_net." "q_out._model.0.bias", "default_policy/value_out/kernel": "_value_branch." "_model.0.weight", "default_policy/value_out/bias": "_value_branch." "_model.0.bias", # Target net. "default_policy/sequential_2/action_1/kernel": "action_model." "action_0._model.0.weight", "default_policy/sequential_2/action_1/bias": "action_model." "action_0._model.0.bias", "default_policy/sequential_2/action_out/kernel": "action_model." "action_out._model.0.weight", "default_policy/sequential_2/action_out/bias": "action_model." "action_out._model.0.bias", "default_policy/sequential_3/q_hidden_0/kernel": "q_net." "q_hidden_0._model.0.weight", "default_policy/sequential_3/q_hidden_0/bias": "q_net." "q_hidden_0._model.0.bias", "default_policy/sequential_3/q_out/kernel": "q_net." "q_out._model.0.weight", "default_policy/sequential_3/q_out/bias": "q_net." "q_out._model.0.bias", "default_policy/value_out_1/kernel": "_value_branch." "_model.0.weight", "default_policy/value_out_1/bias": "_value_branch." "_model.0.bias", } env = SimpleEnv batch_size = 100 if env is SimpleEnv: obs_size = (batch_size, 1) actions = np.random.random(size=(batch_size, 1)) elif env == "CartPole-v0": obs_size = (batch_size, 4) actions = np.random.randint(0, 2, size=(batch_size, )) else: obs_size = (batch_size, 3) actions = np.random.random(size=(batch_size, 1)) # Batch of size=n. input_ = self._get_batch_helper(obs_size, actions, batch_size) # Simply compare loss values AND grads of all frameworks with each # other. prev_fw_loss = weights_dict = None expect_c, expect_a, expect_e, expect_t = None, None, None, None # History of tf-updated NN-weights over n training steps. tf_updated_weights = [] # History of input batches used. tf_inputs = [] for fw, sess in framework_iterator( config, frameworks=("tf", "torch"), session=True): # Generate Trainer and get its default Policy object. trainer = sac.SACTrainer(config=config, env=env) policy = trainer.get_policy() p_sess = None if sess: p_sess = policy.get_session() # Set all weights (of all nets) to fixed values. if weights_dict is None: assert fw == "tf" # Start with the tf vars-dict. weights_dict = policy.get_weights() else: assert fw == "torch" # Then transfer that to torch Model. model_dict = self._translate_weights_to_torch( weights_dict, map_) policy.model.load_state_dict(model_dict) policy.target_model.load_state_dict(model_dict) if fw == "tf": log_alpha = weights_dict["default_policy/log_alpha"] elif fw == "torch": # Actually convert to torch tensors. input_ = policy._lazy_tensor_dict(input_) input_ = {k: input_[k] for k in input_.keys()} log_alpha = policy.model.log_alpha.detach().numpy()[0] # Only run the expectation once, should be the same anyways # for all frameworks. if expect_c is None: expect_c, expect_a, expect_e, expect_t = \ self._sac_loss_helper(input_, weights_dict, sorted(weights_dict.keys()), log_alpha, fw, gamma=config["gamma"], sess=sess) # Get actual outs and compare to expectation AND previous # framework. c=critic, a=actor, e=entropy, t=td-error. if fw == "tf": c, a, e, t, tf_c_grads, tf_a_grads, tf_e_grads = \ p_sess.run([ policy.critic_loss, policy.actor_loss, policy.alpha_loss, policy.td_error, policy.optimizer().compute_gradients( policy.critic_loss[0], policy.model.q_variables()), policy.optimizer().compute_gradients( policy.actor_loss, policy.model.policy_variables()), policy.optimizer().compute_gradients( policy.alpha_loss, policy.model.log_alpha)], feed_dict=policy._get_loss_inputs_dict( input_, shuffle=False)) tf_c_grads = [g for g, v in tf_c_grads] tf_a_grads = [g for g, v in tf_a_grads] tf_e_grads = [g for g, v in tf_e_grads] elif fw == "torch": loss_torch(policy, policy.model, None, input_) c, a, e, t = policy.critic_loss, policy.actor_loss, \ policy.alpha_loss, policy.td_error # Test actor gradients. policy.actor_optim.zero_grad() assert all(v.grad is None for v in policy.model.q_variables()) assert all( v.grad is None for v in policy.model.policy_variables()) assert policy.model.log_alpha.grad is None a.backward() # `actor_loss` depends on Q-net vars (but these grads must # be ignored and overridden in critic_loss.backward!). assert not any(v.grad is None for v in policy.model.q_variables()) assert not all( torch.mean(v.grad) == 0 for v in policy.model.policy_variables()) assert not all( torch.min(v.grad) == 0 for v in policy.model.policy_variables()) assert policy.model.log_alpha.grad is None # Compare with tf ones. torch_a_grads = [ v.grad for v in policy.model.policy_variables() ] for tf_g, torch_g in zip(tf_a_grads, torch_a_grads): if tf_g.shape != torch_g.shape: check(tf_g, np.transpose(torch_g)) else: check(tf_g, torch_g) # Test critic gradients. policy.critic_optims[0].zero_grad() assert all( torch.mean(v.grad) == 0.0 for v in policy.model.q_variables()) assert all( torch.min(v.grad) == 0.0 for v in policy.model.q_variables()) assert policy.model.log_alpha.grad is None c[0].backward() assert not all( torch.mean(v.grad) == 0 for v in policy.model.q_variables()) assert not all( torch.min(v.grad) == 0 for v in policy.model.q_variables()) assert policy.model.log_alpha.grad is None # Compare with tf ones. torch_c_grads = [v.grad for v in policy.model.q_variables()] for tf_g, torch_g in zip(tf_c_grads, torch_c_grads): if tf_g.shape != torch_g.shape: check(tf_g, np.transpose(torch_g)) else: check(tf_g, torch_g) # Compare (unchanged(!) actor grads) with tf ones. torch_a_grads = [ v.grad for v in policy.model.policy_variables() ] for tf_g, torch_g in zip(tf_a_grads, torch_a_grads): if tf_g.shape != torch_g.shape: check(tf_g, np.transpose(torch_g)) else: check(tf_g, torch_g) # Test alpha gradient. policy.alpha_optim.zero_grad() assert policy.model.log_alpha.grad is None e.backward() assert policy.model.log_alpha.grad is not None check(policy.model.log_alpha.grad, tf_e_grads) check(c, expect_c) check(a, expect_a) check(e, expect_e) check(t, expect_t) # Store this framework's losses in prev_fw_loss to compare with # next framework's outputs. if prev_fw_loss is not None: check(c, prev_fw_loss[0]) check(a, prev_fw_loss[1]) check(e, prev_fw_loss[2]) check(t, prev_fw_loss[3]) prev_fw_loss = (c, a, e, t) # Update weights from our batch (n times). for update_iteration in range(10): print("train iteration {}".format(update_iteration)) if fw == "tf": in_ = self._get_batch_helper(obs_size, actions, batch_size) tf_inputs.append(in_) # Set a fake-batch to use # (instead of sampling from replay buffer). trainer.optimizer._fake_batch = in_ trainer.train() updated_weights = policy.get_weights() # Net must have changed. if tf_updated_weights: check( updated_weights[ "default_policy/sequential/action_1/kernel"], tf_updated_weights[-1][ "default_policy/sequential/action_1/kernel"], false=True) tf_updated_weights.append(updated_weights) # Compare with updated tf-weights. Must all be the same. else: tf_weights = tf_updated_weights[update_iteration] in_ = tf_inputs[update_iteration] # Set a fake-batch to use # (instead of sampling from replay buffer). trainer.optimizer._fake_batch = in_ trainer.train() # Compare updated model. for tf_key in sorted(tf_weights.keys())[2:10]: tf_var = tf_weights[tf_key] torch_var = policy.model.state_dict()[map_[tf_key]] if tf_var.shape != torch_var.shape: check(tf_var, np.transpose(torch_var), rtol=0.05) else: check(tf_var, torch_var, rtol=0.05) # And alpha. check(policy.model.log_alpha, tf_weights["default_policy/log_alpha"]) # Compare target nets. for tf_key in sorted(tf_weights.keys())[10:18]: tf_var = tf_weights[tf_key] torch_var = policy.target_model.state_dict()[map_[ tf_key]] if tf_var.shape != torch_var.shape: check(tf_var, np.transpose(torch_var), rtol=0.05) else: check(tf_var, torch_var, rtol=0.05) def _get_batch_helper(self, obs_size, actions, batch_size): return { SampleBatch.CUR_OBS: np.random.random(size=obs_size), SampleBatch.ACTIONS: actions, SampleBatch.REWARDS: np.random.random(size=(batch_size, )), SampleBatch.DONES: np.random.choice( [True, False], size=(batch_size, )), SampleBatch.NEXT_OBS: np.random.random(size=obs_size) } def _sac_loss_helper(self, train_batch, weights, ks, log_alpha, fw, gamma, sess): """Emulates SAC loss functions for tf and torch.""" # ks: # 0=log_alpha # 1=target log-alpha (not used) # 2=action hidden bias # 3=action hidden kernel # 4=action out bias # 5=action out kernel # 6=Q hidden bias # 7=Q hidden kernel # 8=Q out bias # 9=Q out kernel # 14=target Q hidden bias # 15=target Q hidden kernel # 16=target Q out bias # 17=target Q out kernel alpha = np.exp(log_alpha) cls = TorchSquashedGaussian if fw == "torch" else SquashedGaussian model_out_t = train_batch[SampleBatch.CUR_OBS] model_out_tp1 = train_batch[SampleBatch.NEXT_OBS] target_model_out_tp1 = train_batch[SampleBatch.NEXT_OBS] # get_policy_output action_dist_t = cls( fc( relu( fc(model_out_t, weights[ks[3]], weights[ks[2]], framework=fw)), weights[ks[5]], weights[ks[4]]), None) policy_t = action_dist_t.deterministic_sample() log_pis_t = action_dist_t.logp(policy_t) if sess: log_pis_t = sess.run(log_pis_t) policy_t = sess.run(policy_t) log_pis_t = np.expand_dims(log_pis_t, -1) # Get policy output for t+1. action_dist_tp1 = cls( fc( relu( fc(model_out_tp1, weights[ks[3]], weights[ks[2]], framework=fw)), weights[ks[5]], weights[ks[4]]), None) policy_tp1 = action_dist_tp1.deterministic_sample() log_pis_tp1 = action_dist_tp1.logp(policy_tp1) if sess: log_pis_tp1 = sess.run(log_pis_tp1) policy_tp1 = sess.run(policy_tp1) log_pis_tp1 = np.expand_dims(log_pis_tp1, -1) # Q-values for the actually selected actions. # get_q_values q_t = fc( relu( fc(np.concatenate( [model_out_t, train_batch[SampleBatch.ACTIONS]], -1), weights[ks[7]], weights[ks[6]], framework=fw)), weights[ks[9]], weights[ks[8]], framework=fw) # Q-values for current policy in given current state. # get_q_values q_t_det_policy = fc( relu( fc(np.concatenate([model_out_t, policy_t], -1), weights[ks[7]], weights[ks[6]], framework=fw)), weights[ks[9]], weights[ks[8]], framework=fw) # Target q network evaluation. # target_model.get_q_values q_tp1 = fc( relu( fc(np.concatenate([target_model_out_tp1, policy_tp1], -1), weights[ks[15]], weights[ks[14]], framework=fw)), weights[ks[17]], weights[ks[16]], framework=fw) q_t_selected = np.squeeze(q_t, axis=-1) q_tp1 -= alpha * log_pis_tp1 q_tp1_best = np.squeeze(q_tp1, axis=-1) dones = train_batch[SampleBatch.DONES] rewards = train_batch[SampleBatch.REWARDS] if fw == "torch": dones = dones.float().numpy() rewards = rewards.numpy() q_tp1_best_masked = (1.0 - dones) * q_tp1_best q_t_selected_target = rewards + gamma * q_tp1_best_masked base_td_error = np.abs(q_t_selected - q_t_selected_target) td_error = base_td_error critic_loss = [ 0.5 * np.mean(np.power(q_t_selected_target - q_t_selected, 2.0)) ] target_entropy = -np.prod((1, )) alpha_loss = -np.mean(log_alpha * (log_pis_t + target_entropy)) actor_loss = np.mean(alpha * log_pis_t - q_t_det_policy) return critic_loss, actor_loss, alpha_loss, td_error def _translate_weights_to_torch(self, weights_dict, map_): model_dict = { map_[k]: convert_to_torch_tensor( np.transpose(v) if re.search("kernel", k) else v) for k, v in weights_dict.items() if re.search("(sequential(/|_1)|value_out/)", k) } return model_dict if __name__ == "__main__": import pytest import sys sys.exit(pytest.main(["-v", __file__]))