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| 1 | +"""A training script of TRPO on OpenAI Gym Mujoco environments. |
| 2 | +
|
| 3 | +This script follows the settings of https://arxiv.org/abs/1709.06560 as much |
| 4 | +as possible. |
| 5 | +""" |
| 6 | +from __future__ import division |
| 7 | +from __future__ import print_function |
| 8 | +from __future__ import unicode_literals |
| 9 | +from __future__ import absolute_import |
| 10 | +from builtins import * # NOQA |
| 11 | +from future import standard_library |
| 12 | +standard_library.install_aliases() # NOQA |
| 13 | + |
| 14 | +import argparse |
| 15 | +import logging |
| 16 | +import os |
| 17 | + |
| 18 | +import chainer |
| 19 | +from chainer import functions as F |
| 20 | +from chainer import links as L |
| 21 | +import gym |
| 22 | +import gym.spaces |
| 23 | +import gym.wrappers |
| 24 | +import numpy as np |
| 25 | + |
| 26 | +import chainerrl |
| 27 | + |
| 28 | + |
| 29 | +def main(): |
| 30 | + |
| 31 | + parser = argparse.ArgumentParser() |
| 32 | + parser.add_argument('--gpu', type=int, default=0, |
| 33 | + help='GPU device ID. Set to -1 to use CPUs only.') |
| 34 | + parser.add_argument('--env', type=str, default='Hopper-v2', |
| 35 | + help='Gym Env ID') |
| 36 | + parser.add_argument('--seed', type=int, default=0, |
| 37 | + help='Random seed [0, 2 ** 32)') |
| 38 | + parser.add_argument('--outdir', type=str, default='results', |
| 39 | + help='Directory path to save output files.' |
| 40 | + ' If it does not exist, it will be created.') |
| 41 | + parser.add_argument('--steps', type=int, default=2 * 10 ** 6, |
| 42 | + help='Total time steps for training.') |
| 43 | + parser.add_argument('--eval-interval', type=int, default=100000, |
| 44 | + help='Interval between evaluation phases in steps.') |
| 45 | + parser.add_argument('--eval-n-runs', type=int, default=100, |
| 46 | + help='Number of episodes ran in an evaluation phase') |
| 47 | + parser.add_argument('--render', action='store_true', default=False, |
| 48 | + help='Render the env') |
| 49 | + parser.add_argument('--demo', action='store_true', default=False, |
| 50 | + help='Run demo episodes, not training') |
| 51 | + parser.add_argument('--load', type=str, default='', |
| 52 | + help='Directory path to load a saved agent data from' |
| 53 | + ' if it is a non-empty string.') |
| 54 | + parser.add_argument('--trpo-update-interval', type=int, default=5000, |
| 55 | + help='Interval steps of TRPO iterations.') |
| 56 | + parser.add_argument('--logger-level', type=int, default=logging.INFO, |
| 57 | + help='Level of the root logger.') |
| 58 | + parser.add_argument('--monitor', action='store_true', |
| 59 | + help='Monitor the env by gym.wrappers.Monitor.' |
| 60 | + ' Videos and additional log will be saved.') |
| 61 | + args = parser.parse_args() |
| 62 | + |
| 63 | + logging.basicConfig(level=args.logger_level) |
| 64 | + |
| 65 | + # Set random seed |
| 66 | + chainerrl.misc.set_random_seed(args.seed, gpus=(args.gpu,)) |
| 67 | + |
| 68 | + args.outdir = chainerrl.experiments.prepare_output_dir(args, args.outdir) |
| 69 | + |
| 70 | + def make_env(test): |
| 71 | + env = gym.make(args.env) |
| 72 | + # Use different random seeds for train and test envs |
| 73 | + env_seed = 2 ** 32 - 1 - args.seed if test else args.seed |
| 74 | + env.seed(env_seed) |
| 75 | + # Cast observations to float32 because our model uses float32 |
| 76 | + env = chainerrl.wrappers.CastObservationToFloat32(env) |
| 77 | + if args.monitor: |
| 78 | + env = gym.wrappers.Monitor(env, args.outdir) |
| 79 | + if args.render: |
| 80 | + env = chainerrl.wrappers.Render(env) |
| 81 | + return env |
| 82 | + |
| 83 | + env = make_env(test=False) |
| 84 | + timestep_limit = env.spec.tags.get( |
| 85 | + 'wrapper_config.TimeLimit.max_episode_steps') |
| 86 | + obs_space = env.observation_space |
| 87 | + action_space = env.action_space |
| 88 | + print('Observation space:', obs_space) |
| 89 | + print('Action space:', action_space) |
| 90 | + |
| 91 | + assert isinstance(obs_space, gym.spaces.Box) |
| 92 | + |
| 93 | + # Normalize observations based on their empirical mean and variance |
| 94 | + obs_normalizer = chainerrl.links.EmpiricalNormalization( |
| 95 | + obs_space.low.size, clip_threshold=5) |
| 96 | + |
| 97 | + # Orthogonal weight initialization is used as OpenAI Baselines does |
| 98 | + winit = chainerrl.initializers.Orthogonal(1.) |
| 99 | + winit_last = chainerrl.initializers.Orthogonal(1e-2) |
| 100 | + |
| 101 | + action_size = action_space.low.size |
| 102 | + policy = chainer.Sequential( |
| 103 | + L.Linear(None, 64, initialW=winit), |
| 104 | + F.tanh, |
| 105 | + L.Linear(None, 64, initialW=winit), |
| 106 | + F.tanh, |
| 107 | + L.Linear(None, action_size, initialW=winit_last), |
| 108 | + chainerrl.policies.GaussianHeadWithStateIndependentCovariance( |
| 109 | + action_size=action_size, |
| 110 | + var_type='diagonal', |
| 111 | + var_func=lambda x: F.exp(2 * x), # Parameterize log std |
| 112 | + var_param_init=0, # log std = 0 => std = 1 |
| 113 | + ), |
| 114 | + ) |
| 115 | + |
| 116 | + vf = chainer.Sequential( |
| 117 | + L.Linear(None, 64, initialW=winit), |
| 118 | + F.tanh, |
| 119 | + L.Linear(None, 64, initialW=winit), |
| 120 | + F.tanh, |
| 121 | + L.Linear(None, 1, initialW=winit), |
| 122 | + ) |
| 123 | + |
| 124 | + if args.gpu >= 0: |
| 125 | + chainer.cuda.get_device_from_id(args.gpu).use() |
| 126 | + policy.to_gpu(args.gpu) |
| 127 | + vf.to_gpu(args.gpu) |
| 128 | + obs_normalizer.to_gpu(args.gpu) |
| 129 | + |
| 130 | + # TRPO's policy is optimized via CG and line search, so it doesn't require |
| 131 | + # a chainer.Optimizer. Only the value function needs it. |
| 132 | + vf_opt = chainer.optimizers.Adam() |
| 133 | + vf_opt.setup(vf) |
| 134 | + |
| 135 | + # Draw the computational graph and save it in the output directory. |
| 136 | + fake_obs = chainer.Variable( |
| 137 | + policy.xp.zeros_like(obs_space.low, dtype=np.float32)[None], |
| 138 | + name='observation') |
| 139 | + chainerrl.misc.draw_computational_graph( |
| 140 | + [policy(fake_obs)], os.path.join(args.outdir, 'policy')) |
| 141 | + chainerrl.misc.draw_computational_graph( |
| 142 | + [vf(fake_obs)], os.path.join(args.outdir, 'vf')) |
| 143 | + |
| 144 | + # Hyperparameters in http://arxiv.org/abs/1709.06560 |
| 145 | + agent = chainerrl.agents.TRPO( |
| 146 | + policy=policy, |
| 147 | + vf=vf, |
| 148 | + vf_optimizer=vf_opt, |
| 149 | + obs_normalizer=obs_normalizer, |
| 150 | + update_interval=args.trpo_update_interval, |
| 151 | + max_kl=0.01, |
| 152 | + conjugate_gradient_max_iter=20, |
| 153 | + conjugate_gradient_damping=1e-1, |
| 154 | + gamma=0.995, |
| 155 | + lambd=0.97, |
| 156 | + vf_epochs=5, |
| 157 | + entropy_coef=0, |
| 158 | + ) |
| 159 | + |
| 160 | + if args.load: |
| 161 | + agent.load(args.load) |
| 162 | + |
| 163 | + if args.demo: |
| 164 | + env = make_env(test=True) |
| 165 | + eval_stats = chainerrl.experiments.eval_performance( |
| 166 | + env=env, |
| 167 | + agent=agent, |
| 168 | + n_steps=None, |
| 169 | + n_episodes=args.eval_n_runs, |
| 170 | + max_episode_len=timestep_limit) |
| 171 | + print('n_runs: {} mean: {} median: {} stdev {}'.format( |
| 172 | + args.eval_n_runs, eval_stats['mean'], eval_stats['median'], |
| 173 | + eval_stats['stdev'])) |
| 174 | + else: |
| 175 | + |
| 176 | + chainerrl.experiments.train_agent_with_evaluation( |
| 177 | + agent=agent, |
| 178 | + env=env, |
| 179 | + eval_env=make_env(test=True), |
| 180 | + outdir=args.outdir, |
| 181 | + steps=args.steps, |
| 182 | + eval_n_steps=None, |
| 183 | + eval_n_episodes=args.eval_n_runs, |
| 184 | + eval_interval=args.eval_interval, |
| 185 | + train_max_episode_len=timestep_limit, |
| 186 | + ) |
| 187 | + |
| 188 | + |
| 189 | +if __name__ == '__main__': |
| 190 | + main() |
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