hybrid_sac_platform.py

# https://github.com/vwxyzjn/cleanrl/blob/master/cleanrl/sac_continuous_action.py

import torch
import torch.nn as nn
import torch.optim as optim
import torch.nn.functional as F
from torch.distributions.categorical import Categorical
from torch.distributions.normal import Normal
from torch.utils.tensorboard import SummaryWriter

from utils import to_gym_action, to_torch_action, gym_to_buffer
from wrappers.platfrom_wrappers import ScaledStateWrapper, PlatformFlattenedActionWrapper, ScaledParameterisedActionWrapper
import gym_platform

import argparse
from distutils.util import strtobool
import collections
import numpy as np
import gym
from gym.wrappers import TimeLimit, Monitor
# import pybullet_envs
from gym.spaces import Discrete, Box, MultiBinary, MultiDiscrete, Space
import time
import random
import os

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description='SAC with 2 Q functions, Online updates')
    # Common arguments
    parser.add_argument('--exp-name',
                        type=str,
                        default=os.path.basename(__file__).rstrip(".py"),
                        help='the name of this experiment')
    parser.add_argument('--gym-id', type=str, default="HopperBulletEnv-v0", help='the id of the gym environment')
    parser.add_argument('--learning-rate', type=float, default=7e-4, help='the learning rate of the optimizer')
    parser.add_argument('--seed', type=int, default=2, help='seed of the experiment')
    parser.add_argument('--episode-length', type=int, default=0, help='the maximum length of each episode')
    parser.add_argument('--total-timesteps', type=int, default=4000000, help='total timesteps of the experiments')
    parser.add_argument('--torch-deterministic',
                        type=lambda x: bool(strtobool(x)),
                        default=True,
                        nargs='?',
                        const=True,
                        help='if toggled, `torch.backends.cudnn.deterministic=False`')
    parser.add_argument('--cuda',
                        type=lambda x: bool(strtobool(x)),
                        default=True,
                        nargs='?',
                        const=True,
                        help='if toggled, cuda will not be enabled by default')
    parser.add_argument('--prod-mode',
                        type=lambda x: bool(strtobool(x)),
                        default=False,
                        nargs='?',
                        const=True,
                        help='run the script in production mode and use wandb to log outputs')
    parser.add_argument('--capture-video',
                        type=lambda x: bool(strtobool(x)),
                        default=False,
                        nargs='?',
                        const=True,
                        help='weather to capture videos of the agent performances (check out `videos` folder)')
    parser.add_argument('--wandb-project-name', type=str, default="cleanRL", help="the wandb's project name")
    parser.add_argument('--wandb-entity', type=str, default=None, help="the entity (team) of wandb's project")
    parser.add_argument('--autotune',
                        type=lambda x: bool(strtobool(x)),
                        default=True,
                        nargs='?',
                        const=True,
                        help='automatic tuning of the entropy coefficient.')

    # Algorithm specific arguments
    parser.add_argument('--buffer-size', type=int, default=10000, help='the replay memory buffer size')
    parser.add_argument('--gamma', type=float, default=0.9, help='the discount factor gamma')
    parser.add_argument(
        '--target-network-frequency',
        type=int,
        default=1,  # Denis Yarats' implementation delays this by 2.
        help="the timesteps it takes to update the target network")
    parser.add_argument('--max-grad-norm', type=float, default=10.0, help='the maximum norm for the gradient clipping')
    parser.add_argument(
        '--batch-size',
        type=int,
        default=128,  # Worked better in my experiments, still have to do ablation on this. Please remind me
        help="the batch size of sample from the reply memory")
    parser.add_argument('--tau', type=float, default=0.1, help="target smoothing coefficient (default: 0.005)")
    parser.add_argument('--alpha', type=float, default=0.2, help="Entropy regularization coefficient.")
    parser.add_argument('--learning-starts', type=int, default=5e3, help="timestep to start learning")

    # Additional hyper parameters for tweaks
    ## Separating the learning rate of the policy and value commonly seen: (Original implementation, Denis Yarats)
    parser.add_argument('--policy-lr',
                        type=float,
                        default=1e-4,
                        help='the learning rate of the policy network optimizer')
    parser.add_argument('--q-lr', type=float, default=1e-3, help='the learning rate of the Q network network optimizer')
    parser.add_argument('--policy-frequency',
                        type=int,
                        default=1,
                        help='delays the update of the actor, as per the TD3 paper.')
    # NN Parameterization
    parser.add_argument('--weights-init',
                        default='xavier',
                        const='xavier',
                        nargs='?',
                        choices=['xavier', "orthogonal", 'uniform'],
                        help='weight initialization scheme for the neural networks.')
    parser.add_argument('--bias-init',
                        default='zeros',
                        const='xavier',
                        nargs='?',
                        choices=['zeros', 'uniform'],
                        help='weight initialization scheme for the neural networks.')
    parser.add_argument('--ent-c',
                        default=-0.25,
                        type=float,
                        help='target entropy of continuous component.')
    parser.add_argument('--ent-d',
                        default=0.25,
                        type=float,
                        help='target entropy of discrete component.')

    args = parser.parse_args()
    if not args.seed:
        args.seed = int(time.time())

# TRY NOT TO MODIFY: setup the environment
experiment_name = f"{args.gym_id}__{args.exp_name}__{args.seed}__{int(time.time())}"
writer = SummaryWriter(f"runs/{experiment_name}")
writer.add_text('hyperparameters',
                "|param|value|\n|-|-|\n%s" % ('\n'.join([f"|{key}|{value}|" for key, value in vars(args).items()])))
if args.prod_mode:
    import wandb
    wandb.init(project=args.wandb_project_name,
               entity=args.wandb_entity,
               sync_tensorboard=True,
               config=vars(args),
               name=experiment_name,
               monitor_gym=True,
               save_code=True)
    writer = SummaryWriter(f"/tmp/{experiment_name}")

# TRY NOT TO MODIFY: seeding
device = torch.device('cuda' if torch.cuda.is_available() and args.cuda else 'cpu')
env = gym.make('Platform-v0')
env = ScaledStateWrapper(env)
env = PlatformFlattenedActionWrapper(env)
env = ScaledParameterisedActionWrapper(env)
random.seed(args.seed)
np.random.seed(args.seed)
torch.manual_seed(args.seed)
torch.backends.cudnn.deterministic = args.torch_deterministic
env.seed(args.seed)
env.action_space.seed(args.seed)
env.observation_space.seed(args.seed)
input_shape = 9
out_c = out_d = 3
if args.capture_video:
    env = Monitor(env, f'videos/{experiment_name}')

# ALGO LOGIC: initialize agent here:
LOG_STD_MAX = 0.0
LOG_STD_MIN = -3.0


def layer_init(layer, weight_gain=1, bias_const=0):
    if isinstance(layer, nn.Linear):
        if args.weights_init == "xavier":
            torch.nn.init.xavier_uniform_(layer.weight, gain=weight_gain)
        elif args.weights_init == "orthogonal":
            torch.nn.init.orthogonal_(layer.weight, gain=weight_gain)
        if args.bias_init == "zeros":
            torch.nn.init.constant_(layer.bias, bias_const)


class Policy(nn.Module):
    def __init__(self, input_shape, out_c, out_d, env):
        super(Policy, self).__init__()
        self.fc1 = nn.Linear(input_shape, 128)  # Better result with slightly wider networks.
        self.mean = nn.Linear(128, out_c)
        self.logstd = nn.Linear(128, out_c)
        self.pi_d = nn.Linear(128, out_d)

        self.apply(layer_init)

    def forward(self, x, device):
        x = torch.Tensor(x).to(device)

        x = F.relu(self.fc1(x))
        mean = torch.tanh(self.mean(x))
        log_std = torch.tanh(self.logstd(x))
        pi_d = self.pi_d(x)
        log_std = LOG_STD_MIN + 0.5 * (LOG_STD_MAX - LOG_STD_MIN) * (log_std + 1)  # From SpinUp / Denis Yarats

        return mean, log_std, pi_d

    def get_action(self, x, device):
        mean, log_std, pi_d = self.forward(x, device)
        std = log_std.exp()
        normal = Normal(mean, std)
        x_t = normal.rsample()  # for reparameterization trick (mean + std * N(0,1))
        action_c = torch.tanh(x_t)
        log_prob_c = normal.log_prob(x_t)
        log_prob_c -= torch.log(1.0 - action_c.pow(2) + 1e-8)

        dist = Categorical(logits=pi_d)
        action_d = dist.sample()
        prob_d = dist.probs
        log_prob_d = torch.log(prob_d + 1e-8)

        return action_c, action_d, log_prob_c, log_prob_d, prob_d

    def to(self, device):
        return super(Policy, self).to(device)

class SoftQNetwork(nn.Module):
    def __init__(self, input_shape, out_c, out_d, layer_init):
        super(SoftQNetwork, self).__init__()
        self.fc1 = nn.Linear(input_shape + out_c, 128)
        self.fc2 = nn.Linear(128, out_d)
        self.apply(layer_init)

    def forward(self, x, a, device):
        x = torch.Tensor(x).to(device)
        x = torch.cat([x, a], 1)
        x = F.relu(self.fc1(x))
        x = self.fc2(x)
        return x


# modified from https://github.com/seungeunrho/minimalRL/blob/master/dqn.py#
class ReplayBuffer():
    def __init__(self, buffer_limit):
        self.buffer = collections.deque(maxlen=buffer_limit)

    def put(self, transition):
        self.buffer.append(transition)

    def sample(self, n):
        mini_batch = random.sample(self.buffer, n)
        s_lst, a_lst, r_lst, s_prime_lst, done_mask_lst = [], [], [], [], []

        for transition in mini_batch:
            s, a, r, s_prime, done_mask = transition
            s_lst.append(s)
            a_lst.append(a)
            r_lst.append(r)
            s_prime_lst.append(s_prime)
            done_mask_lst.append(done_mask)

        return np.array(s_lst), np.array(a_lst), \
               np.array(r_lst), np.array(s_prime_lst), \
               np.array(done_mask_lst)


rb = ReplayBuffer(args.buffer_size)
pg = Policy(input_shape, out_c, out_d, env).to(device)
qf1 = SoftQNetwork(input_shape, out_c, out_d, layer_init).to(device)
qf2 = SoftQNetwork(input_shape, out_c, out_d, layer_init).to(device)
qf1_target = SoftQNetwork(input_shape, out_c, out_d, layer_init).to(device)
qf2_target = SoftQNetwork(input_shape, out_c, out_d, layer_init).to(device)
qf1_target.load_state_dict(qf1.state_dict())
qf2_target.load_state_dict(qf2.state_dict())
values_optimizer = optim.Adam(list(qf1.parameters()) + list(qf2.parameters()), lr=args.q_lr)
policy_optimizer = optim.Adam(list(pg.parameters()), lr=args.policy_lr)
loss_fn = nn.MSELoss()

# Automatic entropy tuning
if args.autotune:
    # target_entropy = -float(out_c)
    target_entropy = args.ent_c
    log_alpha = torch.zeros(1, requires_grad=True, device=device)
    alpha = log_alpha.exp().detach().cpu().item()
    a_optimizer = optim.Adam([log_alpha], lr=1e-4)

    # target_entropy_d = -0.98 * np.log(1/out_d)
    target_entropy_d = args.ent_d
    log_alpha_d = torch.zeros(1, requires_grad=True, device=device)
    alpha_d = log_alpha_d.exp().detach().cpu().item()
    a_d_optimizer = optim.Adam([log_alpha_d], lr=1e-4)
else:
    alpha = args.alpha
    alpha_d = args.alpha

# TRY NOT TO MODIFY: start the game
global_episode = 0
(obs, _), done = env.reset(), False
episode_reward, episode_length = 0., 0

for global_step in range(1, args.total_timesteps + 1):
    # ALGO LOGIC: put action logic here
    if global_step < args.learning_starts:
        action_ = env.action_space.sample()
        action_ = gym_to_buffer(action_)
        action = [action_[0], action_[1:]]
    else:
        action_c, action_d, _, _, _ = pg.get_action([obs], device)
        action = to_gym_action(action_c, action_d)

    # TRY NOT TO MODIFY: execute the game and log data.
    (next_obs, _), reward, done, _ = env.step(action)
    rb.put((obs, gym_to_buffer(action), reward, next_obs, done))
    episode_reward += reward
    episode_length += 1
    obs = np.array(next_obs)

    # ALGO LOGIC: training.
    if len(rb.buffer) > args.batch_size:  # starts update as soon as there is enough data.
        s_obs, s_actions, s_rewards, s_next_obses, s_dones = rb.sample(args.batch_size)
        with torch.no_grad():
            next_state_actions_c, next_state_actions_d, next_state_log_pi_c, next_state_log_pi_d, next_state_prob_d = pg.get_action(s_next_obses, device)
            qf1_next_target = qf1_target.forward(s_next_obses, next_state_actions_c, device)
            qf2_next_target = qf2_target.forward(s_next_obses, next_state_actions_c, device)

            min_qf_next_target = next_state_prob_d * (torch.min(qf1_next_target, qf2_next_target) - alpha * next_state_prob_d * next_state_log_pi_c - alpha_d * next_state_log_pi_d)
            next_q_value = torch.Tensor(s_rewards).to(
                device) + (1 - torch.Tensor(s_dones).to(device)) * args.gamma * (min_qf_next_target.sum(1)).view(-1)

        s_actions_c, s_actions_d = to_torch_action(s_actions, device)
        qf1_a_values = qf1.forward(s_obs, s_actions_c, device).gather(1, s_actions_d.long().view(-1, 1).to(device)).squeeze().view(-1)
        qf2_a_values = qf2.forward(s_obs, s_actions_c, device).gather(1, s_actions_d.long().view(-1, 1).to(device)).squeeze().view(-1)
        qf1_loss = loss_fn(qf1_a_values, next_q_value)
        qf2_loss = loss_fn(qf2_a_values, next_q_value)
        qf_loss = (qf1_loss + qf2_loss) / 2

        values_optimizer.zero_grad()
        qf_loss.backward()
        values_optimizer.step()

        if global_step % args.policy_frequency == 0:  # TD 3 Delayed update support
            for _ in range(
                    args.policy_frequency):  # compensate for the delay by doing 'actor_update_interval' instead of 1
                actions_c, actions_d, log_pi_c, log_pi_d, prob_d = pg.get_action(s_obs, device)
                qf1_pi = qf1.forward(s_obs, actions_c, device)
                qf2_pi = qf2.forward(s_obs, actions_c, device)
                min_qf_pi = torch.min(qf1_pi, qf2_pi)

                policy_loss_d = (prob_d * (alpha_d * log_pi_d - min_qf_pi)).sum(1).mean()
                policy_loss_c = (prob_d * (alpha * prob_d * log_pi_c - min_qf_pi)).sum(1).mean()
                policy_loss = policy_loss_d + policy_loss_c

                policy_optimizer.zero_grad()
                policy_loss.backward()
                policy_optimizer.step()

                if args.autotune:
                    with torch.no_grad():
                        a_c, a_d, lpi_c, lpi_d, p_d = pg.get_action(s_obs, device)
                    alpha_loss = (-log_alpha * p_d * (p_d * lpi_c + target_entropy)).sum(1).mean()
                    alpha_d_loss = (-log_alpha_d * p_d * (lpi_d + target_entropy_d)).sum(1).mean()

                    a_optimizer.zero_grad()
                    alpha_loss.backward()
                    a_optimizer.step()
                    alpha = log_alpha.exp().detach().cpu().item()

                    a_d_optimizer.zero_grad()
                    alpha_d_loss.backward()
                    a_d_optimizer.step()
                    alpha_d = log_alpha_d.exp().detach().cpu().item()

        # update the target network
        if global_step % args.target_network_frequency == 0:
            for param, target_param in zip(qf1.parameters(), qf1_target.parameters()):
                target_param.data.copy_(args.tau * param.data + (1 - args.tau) * target_param.data)
            for param, target_param in zip(qf2.parameters(), qf2_target.parameters()):
                target_param.data.copy_(args.tau * param.data + (1 - args.tau) * target_param.data)

    if len(rb.buffer) > args.batch_size and global_step % 100 == 0:
        writer.add_scalar("losses/soft_q_value_1_loss", qf1_loss.item(), global_step)
        writer.add_scalar("losses/soft_q_value_2_loss", qf2_loss.item(), global_step)
        writer.add_scalar("losses/qf_loss", qf_loss.item(), global_step)
        writer.add_scalar("losses/policy_loss", policy_loss.item(), global_step)
        writer.add_scalar("losses/alpha", alpha, global_step)
        # NOTE: additional changes from cleanrl
        writer.add_scalar("losses/alpha_d", alpha_d, global_step)
        writer.add_histogram("actions/discrete", action[0]+1, global_step)
        writer.add_histogram("actions/run", action[1][0], global_step)
        writer.add_histogram("actions/hop", action[1][1], global_step)
        writer.add_histogram("actions/leap", action[1][2], global_step)
        writer.add_scalar("debug/ent_bonus", (- alpha * next_state_prob_d * next_state_log_pi_c - alpha_d * next_state_log_pi_d).sum(1).mean().item(), global_step)
        writer.add_scalar("debug/next_q", next_q_value.mean().item(), global_step)
        writer.add_scalar("debug/policy_loss_c", policy_loss_c.item(), global_step)
        writer.add_scalar("debug/policy_loss_d", policy_loss_d.item(), global_step)
        writer.add_scalar("debug/policy_ent_d", -(prob_d*log_pi_d).sum(1).mean().item(), global_step)
        writer.add_scalar("debug/mean_q", min_qf_pi.mean().item(), global_step)
        writer.add_scalar("debug/mean_r", s_rewards.mean(), global_step)
        writer.add_histogram("debug_q/q_0", min_qf_pi[:, 0].mean().item(), global_step)
        writer.add_histogram("debug_q/q_1", min_qf_pi[:, 1].mean().item(), global_step)
        writer.add_histogram("debug_q/q_2", min_qf_pi[:, 2].mean().item(), global_step)
        writer.add_histogram("debug_pi/pi_0", prob_d[:, 0].mean().item(), global_step)
        writer.add_histogram("debug_pi/pi_1", prob_d[:, 1].mean().item(), global_step)
        writer.add_histogram("debug_pi/pi_2", prob_d[:, 2].mean().item(), global_step)
        if args.autotune:
            writer.add_scalar("losses/alpha_loss", alpha_loss.item(), global_step)
            writer.add_scalar("losses/alpha_d_loss", alpha_d_loss.item(), global_step)

    if done:
        global_episode += 1  # Outside the loop already means the epsiode is done
        writer.add_scalar("charts/episode_reward", episode_reward, global_step)
        writer.add_scalar("charts/episode_length", episode_length, global_step)
        # Terminal verbosity
        if global_episode % 10 == 0:
            print(f"Episode: {global_episode} Step: {global_step}, Ep. Reward: {episode_reward}")

        # Reseting what need to be
        (obs, _), done = env.reset(), False
        episode_reward, episode_length = 0., 0

writer.close()
env.close()

# save the policy
torch.save(pg.state_dict(), 'platform.pth')