def __init__(self,
lr,
state_shape,
num_actions,
batch_size,
max_mem_size=100000):
self.lr = lr
self.gamma = 0.99
self.action_space = list(range(num_actions))
self.batch_size = batch_size
self.epsilon = Lerper(start=1.0, end=0.01, num_steps=2000)
self.importance_exp = Lerper(start=0.4, end=1.0, num_steps=100000)
self.priority_exp = 0.6
self.memory = PrioritizedReplayBuffer(max_mem_size, {
"obs": {
"shape": state_shape
},
"act": {
"shape": 1
},
"rew": {},
"next_obs": {
"shape": state_shape
},
"done": {
"shape": 1
}
},
alpha=self.priority_exp)
self.net = Network(lr, state_shape, num_actions)
def get_replay_buffer(policy,
env,
use_prioritized_rb=False,
use_nstep_rb=False,
n_step=1,
size=None):
if policy is None or env is None:
return None
obs_shape = get_space_size(env.observation_space)
kwargs = get_default_rb_dict(policy.memory_capacity, env)
if size is not None:
kwargs["size"] = size
# on-policy policy
if not issubclass(type(policy), OffPolicyAgent):
kwargs["size"] = policy.horizon
kwargs["env_dict"].pop("next_obs")
kwargs["env_dict"].pop("rew")
# TODO: Remove done. Currently cannot remove because of cpprb implementation
# kwargs["env_dict"].pop("done")
kwargs["env_dict"]["logp"] = {}
kwargs["env_dict"]["ret"] = {}
kwargs["env_dict"]["adv"] = {}
if is_discrete(env.action_space):
kwargs["env_dict"]["act"]["dtype"] = np.int32
return ReplayBuffer(**kwargs)
# N-step prioritized
if use_prioritized_rb and use_nstep_rb:
kwargs["Nstep"] = {
"size": n_step,
"gamma": policy.discount,
"rew": "rew",
"next": "next_obs"
}
return PrioritizedReplayBuffer(**kwargs)
if len(obs_shape) == 3:
kwargs["env_dict"]["obs"]["dtype"] = np.ubyte
kwargs["env_dict"]["next_obs"]["dtype"] = np.ubyte
# prioritized
if use_prioritized_rb:
return PrioritizedReplayBuffer(**kwargs)
# N-step
if use_nstep_rb:
kwargs["Nstep"] = {
"size": n_step,
"gamma": policy.discount,
"rew": "rew",
"next": "next_obs"
}
return ReplayBuffer(**kwargs)
return ReplayBuffer(**kwargs)
def test_per_nstep(self):
"""
PrioritizedReplayBuffer.on_episode_end() ignores Exception
Ref: https://gitlab.com/ymd_h/cpprb/-/issues/111
"""
rb = PrioritizedReplayBuffer(32, {
"rew": {},
"done": {}
},
Nstep={
"size": 4,
"rew": "rew",
"gamma": 0.5
})
for _ in range(10):
rb.add(rew=0.5, done=0.0)
rb.add(rew=0.5, done=1.0)
rb.on_episode_end()
s = rb.sample(16)
self.assertIn("discounts", s)
def test_save_cache_with_stack_compress(self):
rb = PrioritizedReplayBuffer(32,
env_dict={
'done': {
'dtype': 'bool'
},
'a': {
'shape': (3)
}
},
stack_compress='a')
a = np.array([0, 1, 2])
for i in range(3):
done = i == 2
rb.add(a=a, done=done)
if done:
rb.on_episode_end()
a += 1
rb.add(a=np.ones(3), done=False)
a_ = rb.get_all_transitions()["a"]
np.testing.assert_allclose(
a_,
np.asarray([[0., 1., 2.], [1., 2., 3.], [2., 3., 4.], [1., 1.,
1.]]))
def test_mp_update_priority(self):
buffer_size = 256
add_size = 200
rb = PrioritizedReplayBuffer(buffer_size,{"obs": {"dtype": int}})
self.assertEqual(rb.get_next_index(),0)
self.assertEqual(rb.get_stored_size(),0)
p = Process(target=add_args,args=[rb,
[{"obs": i, "priorities": 0}
for i in range(add_size)]])
p.start()
p.join()
self.assertEqual(rb.get_next_index(),add_size % buffer_size)
self.assertEqual(rb.get_stored_size(),min(add_size,buffer_size))
s = rb.sample(1,beta=1.0)
one_hot = s["indexes"][0]
rb.update_priorities([one_hot],[1e+8])
self.assertEqual(rb.get_next_index(),add_size % buffer_size)
self.assertEqual(rb.get_stored_size(),min(add_size,buffer_size))
s = rb.sample(100,beta=1.0)
self.assertTrue((s["obs"] >= 0).all())
self.assertTrue((s["obs"] < add_size).all())
u, counts = np.unique(s["obs"],return_counts=True)
self.assertEqual(u[counts.argmax()],one_hot)
def get_replay_buffer(policy,
env,
use_prioritized_rb=False,
use_nstep_rb=False,
n_step=1,
size=None):
if policy is None or env is None:
return None
obs_shape = get_space_size(env.observation_space)
kwargs = get_default_rb_dict(policy.memory_capacity, env)
if size is not None:
kwargs['size'] = size
# TODO(sff1019): Add on-policy behaviour
# TODO(sff1019): Add N-step prioritized
if len(obs_shape) == 3:
kwargs['env_dict']['obs']['dtype'] = np.ubyte
kwargs['env_dict']['next_obs']['dtype'] = np.ubtye
if use_prioritized_rb:
return PrioritizedReplayBuffer(**kwargs)
return ReplayBuffer(**kwargs)
def __init__(self, args):
#self.memory = deque(maxlen=args.buffer_size)
self.memory = PrioritizedReplayBuffer(
args.buffer_size, {
"obs": {
"shape": (64, 64, 6)
},
"act": {},
"rew": {},
"next_obs": {
"shape": (64, 64, 6)
},
"terminal": {}
})
#self.priority = deque(maxlen=args.buffer_size)
self.length = 0
self.args = args
def __init__(self, args, capacity, env):
# Initial importance sampling weight β, annealed to 1 over course of training
self.priority_weight = args.priority_weight
self.n = args.multi_step
self.device = args.device
if args.mmap:
os.makedirs('memories/', exist_ok=True)
mmap_prefix = 'memories/mm'
else:
mmap_prefix = None
self.buffer = PrioritizedReplayBuffer(
capacity,
{
"obs": {
"shape": env.observation_space.shape,
"dtype": env.observation_space.dtype
},
"next_obs": {
"shape": env.observation_space.shape,
"dtype": env.observation_space.dtype
},
"act": {
"shape": 1,
"dtype": env.action_space.dtype
},
"rew": {
"dtype": np.float32
},
"done": {
"dtype": np.uint8
},
},
Nstep={
"size": self.n,
"gamma": args.discount,
"rew": "rew",
"next": "next_obs",
},
mmap_prefix=mmap_prefix,
alpha=args.priority_exponent,
# next_of="obs",
# stack_compress="obs",
)
def test_PrioritizedReplayBuffer_with_single_step_with_priorities(self):
buffer_size = 256
obs_shape = (3, 4)
batch_size = 10
rb = PrioritizedReplayBuffer(buffer_size,
{"obs": {
"shape": obs_shape
}})
v = {"obs": np.ones(shape=obs_shape), "priorities": 0.5}
rb.add(**v)
rb.sample(batch_size)
for _ in range(100):
rb.add(**v)
rb.sample(batch_size)
def test_PrioritizedReplayBuffer_with_multiple_steps(self):
buffer_size = 256
obs_shape = (3, 4)
step_size = 32
batch_size = 10
rb = PrioritizedReplayBuffer(buffer_size,
{"obs": {
"shape": obs_shape
}})
v = {"obs": np.ones(shape=(step_size, *obs_shape))}
rb.add(**v)
rb.sample(batch_size)
for _ in range(100):
rb.add(**v)
rb.sample(batch_size)
def test_cpdef_super(self):
buffer_size = 256
obs_dim = 15
act_dim = 3
prb = PrioritizedReplayBuffer(
buffer_size, {
"obs": {
"shape": obs_dim
},
"act": {
"shape": act_dim
},
"rew": {},
"next_obs": {
"shape": obs_dim
},
"done": {}
})
prb.clear()
def test_prioritized_nstep(self):
rb = PrioritizedReplayBuffer(32, {
"obs": {
"shape": (16, 16)
},
'rew': {},
'done': {}
},
next_of="obs",
stack_compress="obs",
Nstep={
"size": 4,
"rew": "rew"
})
self.assertIs(
rb.add(obs=(np.ones((16, 16))),
next_obs=(np.ones((16, 16))),
rew=1,
done=0), None)
self.assertIs(
rb.add(obs=(np.ones((16, 16))),
next_obs=(np.ones((16, 16))),
rew=1,
done=0), None)
self.assertIs(
rb.add(obs=(np.ones((16, 16))),
next_obs=(np.ones((16, 16))),
rew=1,
done=0), None)
self.assertEqual(
rb.add(obs=(np.ones((16, 16))),
next_obs=(np.ones((16, 16))),
rew=1,
done=0), 0)
def test_buffer_size(self):
buffer_size = 1000
obs_dim = 3
act_dim = 1
rb = ReplayBuffer(
buffer_size, {
"obs": {
"shape": obs_dim
},
"act": {
"shape": act_dim
},
"rew": {},
"next_obs": {
"shape": obs_dim
},
"done": {}
})
prb = PrioritizedReplayBuffer(
buffer_size, {
"obs": {
"shape": obs_dim
},
"act": {
"shape": act_dim
},
"rew": {},
"next_obs": {
"shape": obs_dim
},
"done": {}
})
self.assertEqual(1000, rb.get_buffer_size())
self.assertEqual(1000, prb.get_buffer_size())
rb._encode_sample([i for i in range(1000)])
def test_multi_processing(self):
buffer_size = 256
rb = PrioritizedReplayBuffer(buffer_size,{"obs": {"dtype": int}})
self.assertEqual(rb.get_next_index(),0)
self.assertEqual(rb.get_stored_size(),0)
p = Process(target=add_args,args=[rb,
[{"obs": i, "priority": 0.5}
for i in range(10)]])
p.start()
p.join()
self.assertEqual(rb.get_next_index(),10)
self.assertEqual(rb.get_stored_size(),10)
s = rb.get_all_transitions()
np.testing.assert_allclose(s["obs"].ravel(),np.arange(10,dtype=int))
def test_read_only_priority(self):
buffer_size = 100
batch_size = 32
env_dict = {"done": {}}
done = np.zeros(2)
ps = np.ones_like(done)
ps.setflags(write=False)
rb = PrioritizedReplayBuffer(buffer_size, env_dict)
rb.add(done=done, priority=ps)
sample = rb.sample(batch_size)
ps2 = sample["weights"]
ps2.setflags(write=False)
rb.update_priorities(sample["indexes"], ps2)
def get_replay_buffer(obs_shape,
action_dim,
buffer_size=int(1e6),
use_prioritized=False):
env_dict = {
"obs": {
"shape": obs_shape
},
"act": {
"shape": action_dim
},
"rew": {},
"next_obs": {
"shape": obs_shape
},
"done": {}
}
rb = PrioritizedReplayBuffer(buffer_size, env_dict) if use_prioritized \
else ReplayBuffer(buffer_size, env_dict)
return rb
def test_per_train(self):
"""
Run train function with PER
"""
rb = PrioritizedReplayBuffer(
32, {
"obs": {
"shape": (3, )
},
"act": {},
"rew": {},
"next_obs": {
"shape": (3, )
},
"done": {}
})
train(rb,
self.env,
lambda obs, step, episode, is_warmup: 1.0,
lambda kwargs, step, episode: 0.5,
max_steps=10)
def test_sample(self):
buffer_size = 500
obs_shape = (84,84,3)
act_dim = 4
rb = PrioritizedReplayBuffer(buffer_size,{"obs": {"shape": obs_shape},
"act": {"shape": act_dim},
"rew": {},
"done": {}})
obs = np.zeros(obs_shape)
act = np.ones(act_dim)
rew = 1
done = 0
rb.add(obs=obs,act=act,rew=rew,done=done)
ps = 1.5
rb.add(obs=obs,act=act,rew=rew,done=done,priorities=ps)
self.assertAlmostEqual(rb.get_max_priority(),1.5)
obs = np.stack((obs,obs))
act = np.stack((act,act))
rew = (1,0)
done = (0.0,1.0)
rb.add(obs=obs,act=act,rew=rew,done=done)
ps = (0.2,0.4)
rb.add(obs=obs,act=act,rew=rew,done=done,priorities=ps)
sample = rb.sample(64)
w = sample["weights"]
i = sample["indexes"]
rb.update_priorities(i,w*w)
def test_add(self):
buffer_size = 500
obs_shape = (84,84,3)
act_dim = 10
rb = PrioritizedReplayBuffer(buffer_size,{"obs": {"shape": obs_shape},
"act": {"shape": act_dim},
"rew": {},
"done": {}})
obs = np.zeros(obs_shape)
act = np.ones(act_dim)
rew = 1
done = 0
rb.add(obs=obs,act=act,rew=rew,done=done)
ps = 1.5
rb.add(obs=obs,act=act,rew=rew,done=done,priorities=ps)
self.assertAlmostEqual(rb.get_max_priority(),1.5)
obs = np.stack((obs,obs))
act = np.stack((act,act))
rew = (1,0)
done = (0.0,1.0)
rb.add(obs=obs,act=act,rew=rew,done=done)
ps = (0.2,0.4)
rb.add(obs=obs,act=act,rew=rew,done=done,priorities=ps)
rb.clear()
self.assertEqual(rb.get_next_index(),0)
self.assertEqual(rb.get_stored_size(),0)
def get_replay_buffer(policy, env, use_prioritized_rb, use_nstep_rb, n_step):
if policy is None or env is None:
return None
kwargs = {
"obs_shape": get_space_size(env.observation_space),
"act_dim": get_space_size(env.action_space),
"size": policy.update_interval
}
# on-policy policy
if not issubclass(type(policy), OffPolicyAgent):
return ReplayBuffer(**kwargs)
# off-policy policy
kwargs["size"] = policy.memory_capacity
# N-step prioritized
if use_prioritized_rb and use_nstep_rb:
kwargs["n_step"] = n_step
kwargs["discount"] = policy.discount
return NstepPrioritizedReplayBuffer(**kwargs)
# prioritized
if use_prioritized_rb:
return PrioritizedReplayBuffer(**kwargs)
# N-step
if use_nstep_rb:
kwargs["n_step"] = n_step
kwargs["discount"] = policy.discount
return NstepReplayBuffer(**kwargs)
if isinstance(kwargs["act_dim"], tuple):
kwargs["act_dim"] = kwargs["act_dim"][0]
return ReplayBuffer(**kwargs)
def test_per_without_TD(self):
"""
Run train function with PER withou TD
Raise TypeError
"""
rb = PrioritizedReplayBuffer(
32, {
"obs": {
"shape": (3, )
},
"act": {},
"rew": {},
"next_obs": {
"shape": (3, )
},
"done": {}
})
with self.assertRaises(TypeError):
train(rb,
self.env,
lambda obs, step, episode, is_warmup: 1.0,
lambda kwargs, step, episode: None,
max_steps=10)
class RainbowAgent:
"""Agent interacting with environment.
Attribute:
env (gym.Env): openAI Gym environment
memory (PrioritizedReplayBuffer): replay memory to store transitions
batch_size (int): batch size for sampling
target_update (int): period for target model's hard update
gamma (float): discount factor
dqn (Network): model to train and select actions
dqn_target (Network): target model to update
optimizer (torch.optim): optimizer for training dqn
transition (list): transition information including
state, action, reward, next_state, done
v_min (float): min value of support
v_max (float): max value of support
atom_size (int): the unit number of support
support (torch.Tensor): support for categorical dqn
use_n_step (bool): whether to use n_step memory
n_step (int): step number to calculate n-step td error
memory_n (ReplayBuffer): n-step replay buffer
"""
def __init__(
self,
env: gym.Env,
memory_size: int,
batch_size: int,
target_update: int,
gamma: float = 0.99,
# PER parameters
alpha: float = 0.2,
beta: float = 0.6,
prior_eps: float = 1e-6,
# Categorical DQN parameters
v_min: float = 0.0,
v_max: float = 200.0,
atom_size: int = 51,
# N-step Learning
n_step: int = 3,
# Convergence parameters
convergence_window: int = 100,
convergence_window_epsilon_p: int = 10,
convergence_avg_score: float = 195.0,
convergence_avg_epsilon: float = 0.0524, # 3 degs converted to rads
convergence_avg_epsilon_p: float = 0.0174, # 1 deg/s converted to rad/s
# Tensorboard parameters
model_name: str = "snake_joint",
):
"""Initialization.
Args:
env (gym.Env): openAI Gym environment
memory_size (int): length of memory
batch_size (int): batch size for sampling
target_update (int): period for target model's hard update
lr (float): learning rate
gamma (float): discount factor
alpha (float): determines how much prioritization is used
beta (float): determines how much importance sampling is used
prior_eps (float): guarantees every transition can be sampled
v_min (float): min value of support
v_max (float): max value of support
atom_size (int): the unit number of support
n_step (int): step number to calculate n-step td error
"""
obs_dim = env.observation_space.shape[0]
action_dim = env.action_space.n
self.env = env
self.batch_size = batch_size
self.target_update = target_update
self.gamma = gamma
# NoisyNet: All attributes related to epsilon are removed
#produces a unique timestamp for each run
run_timestamp=str(
#returns number of day and number of month
str(time.localtime(time.time())[2]) + "_" +
str(time.localtime(time.time())[1]) + "_" +
#returns hour, minute and second
str(time.localtime(time.time())[3]) + "_" +
str(time.localtime(time.time())[4]) + "_" +
str(time.localtime(time.time())[5])
)
#Will write scalars that can be visualized using tensorboard in the directory "runLogs/timestamp"
self.writer = SummaryWriter("runLogs/" + run_timestamp)
# device: cpu / gpu
self.device = torch.device(
"cuda" if torch.cuda.is_available() else "cpu"
)
print(self.device)
# PER
# memory for 1-step Learning
self.beta = beta
self.prior_eps = prior_eps
self.memory = PrioritizedReplayBuffer(
memory_size,
{
"obs": {"shape": (obs_dim,)},
"act": {"shape": (1,)},
"rew": {},
"next_obs": {"shape": (obs_dim,)},
"done": {}
},
alpha=alpha
)
# memory for N-step Learning
self.use_n_step = True if n_step > 1 else False
if self.use_n_step:
self.n_step = n_step
self.memory_n = ReplayBuffer(
memory_size,
{
"obs": {"shape": (obs_dim,)},
"act": {"shape": (1,)},
"rew": {},
"next_obs": {"shape": (obs_dim,)},
"done": {}
},
Nstep={
"size": n_step,
"gamma": gamma,
"rew": "rew",
"next": "next_obs"
}
)
# Categorical DQN parameters
self.v_min = v_min
self.v_max = v_max
self.atom_size = atom_size
self.support = torch.linspace(
self.v_min, self.v_max, self.atom_size
).to(self.device)
# networks: dqn, dqn_target
self.dqn = Network(
obs_dim, action_dim, self.atom_size, self.support
).to(self.device)
self.dqn_target = Network(
obs_dim, action_dim, self.atom_size, self.support
).to(self.device)
self.dqn_target.load_state_dict(self.dqn.state_dict())
self.dqn_target.eval()
# optimizer
self.optimizer = optim.Adam(self.dqn.parameters(),0.0001)
# transition to store in memory
self.transition = list()
# mode: train / test
self.is_test = False
# Custom tensorboard object
# self.tensorboard = RainbowTensorBoard(
# log_dir="single_joint_logs/{}-{}".format(
# model_name,
# datetime.now().strftime("%m-%d-%Y-%H_%M_%S")
# )
# )
# Convergence criterion
self.convergence_window = convergence_window
self.convergence_window_epsilon_p = convergence_window_epsilon_p
self.convergence_avg_score = convergence_avg_score
self.convergence_avg_epsilon = convergence_avg_epsilon
self.convergence_avg_epsilon_p = convergence_avg_epsilon_p
def select_action(self, state: np.ndarray) -> np.ndarray:
"""Select an action from the input state."""
# NoisyNet: no epsilon greedy action selection
selected_action = self.dqn(
torch.FloatTensor(state).to(self.device)
).argmax()
selected_action = selected_action.detach().cpu().numpy()
if not self.is_test:
self.transition = [state, selected_action]
return selected_action
def step(self, action: np.ndarray, score:int) -> Tuple[np.ndarray, np.float64, bool]:
"""Take an action and return the response of the env."""
next_state, reward, done, _ = self.env.step(action,score)
if not self.is_test:
self.transition += [reward, next_state, done]
# N-step transition
if self.use_n_step:
idx = self.memory_n.add(
**dict(
zip(["obs", "act", "rew", "next_obs", "done"], self.transition)
)
)
one_step_transition = [ v[idx] for _,v in self.memory_n.get_all_transitions().items()] if idx else None
# 1-step transition
else:
one_step_transition = self.transition
# add a single step transition
if one_step_transition:
self.memory.add(
**dict(
zip(["obs", "act", "rew", "next_obs", "done"], one_step_transition)
)
)
return next_state, reward, done
def update_model(self,frame_idx:int) -> torch.Tensor:
"""Update the model by gradient descent.
shape of elementwise_loss = [128,51]
shape of loss = ([])
shape of weights ([128,1)]
"""
# PER needs beta to calculate weights
samples = self.memory.sample(self.batch_size, beta=self.beta)
weights = torch.FloatTensor(
samples["weights"].reshape(-1, 1)
).to(self.device)
indices = samples["indexes"]
#rospy.loginfo(samples.keys())
#rospy.loginfo(weights.shape)
#rospy.loginfo(indices.shape())
#torch.save(self.dqn.state_dict(),str("checkpoint_"+str(time.time())))
# 1-step Learning loss
elementwise_loss = self._compute_dqn_loss(samples, self.gamma)
# PER: importance sampling before average
loss = torch.mean(elementwise_loss * weights)
self.writer.add_scalar('update_model/Lossv0', loss.detach().item(),frame_idx )
# N-step Learning loss
# we are gonna combine 1-step loss and n-step loss so as to
# prevent high-variance. The original rainbow employs n-step loss only.
if self.use_n_step:
gamma = self.gamma ** self.n_step
samples = {k: [v[i] for i in indices] for k,v in self.memory_n.get_all_transitions().items()}
elementwise_loss_n_loss = self._compute_dqn_loss(samples, gamma)
elementwise_loss += elementwise_loss_n_loss
#rospy.loginfo(elementwise_loss_n_loss.shape)
#rospy.loginfo(elementwise_loss.shape)
# PER: importance sampling before average
loss = torch.mean(elementwise_loss * weights)
rospy.loginfo(
f"{elementwise_loss}"
)
self.optimizer.zero_grad()
self.writer.add_scalar('update_model/Lossv1', loss.detach().item(),frame_idx )
#From pytorch doc: backward() Computes the gradient of current tensor w.r.t. graph leaves.
#self.writer.add_image("loss gradient before", loss, frame_idx)
loss.backward()
#self.writer.add_image("loss gradient after", loss, frame_idx)
self.writer.add_scalar('update_model/Lossv2', loss.detach().item(),frame_idx )
clip_grad_norm_(self.dqn.parameters(), 10.0)
self.optimizer.step()
# PER: update priorities
loss_for_prior = elementwise_loss.detach().cpu().numpy()
new_priorities = loss_for_prior + self.prior_eps
self.memory.update_priorities(indices, new_priorities)
# NoisyNet: reset noise
self.dqn.reset_noise()
self.dqn_target.reset_noise()
#rospy.loginfo("second")
#rospy.loginfo(loss.shape)
#rospy.loginfo("loss dimension = " + loss.ndim() )
#rospy.loginfo("loss = " + str(loss.detach().item()) + "type = " + str(type(loss.detach().item()) ) )
self.writer.add_scalar('update_model/Loss', loss.detach().item(),frame_idx )
return loss.detach().item()
def train(self, num_frames: int):
"""Train the agent."""
self.is_test = False
state = self.env.reset()
update_cnt = 0
losses = []
scores = []
score = 0
for frame_idx in tqdm(range(1, num_frames + 1)):
action = self.select_action(state)
next_state, reward, done = self.step(action,score)
state = next_state
score += reward
# NoisyNet: removed decrease of epsilon
# PER: increase beta
fraction = min(frame_idx / num_frames, 1.0)
self.beta = self.beta + fraction * (1.0 - self.beta)
# if episode ends
if done:
#rospy.loginfo("logging for done")
self.writer.add_scalar('train/score', score, frame_idx)
self.writer.add_scalar('train/final_epsilon', state[6], frame_idx)
self.writer.add_scalar('train/epsilon_p', state[7], frame_idx)
state = self.env.reset()
scores.append(score)
score = 0
# if training is ready
if self.memory.get_stored_size() >= self.batch_size:
#frame_id given as argument for logging by self.writer.
#rospy.loginfo("frame_idx= " + str(frame_idx) + "type = " + str(type(frame_idx)))
loss = self.update_model(frame_idx)
losses.append(loss)
update_cnt += 1
# if hard update is needed
if update_cnt % self.target_update == 0:
self._target_hard_update(loss)
self.env.close()
def test(self) -> List[np.ndarray]:
"""Test the agent."""
self.is_test = True
state = self.env.reset()
done = False
score = 0
frames = []
while not done:
frames.append(self.env.render(mode="rgb_array"))
action = self.select_action(state)
next_state, reward, done = self.step(action)
state = next_state
score += reward
print("score: ", score)
self.env.close()
return frames
def _compute_dqn_loss(self, samples: Dict[str, np.ndarray], gamma: float) -> torch.Tensor:
"""Return categorical dqn loss."""
device = self.device # for shortening the following lines
state = torch.FloatTensor(samples["obs"]).to(device)
next_state = torch.FloatTensor(samples["next_obs"]).to(device)
action = torch.LongTensor(samples["act"]).to(device)
reward = torch.FloatTensor(np.array(samples["rew"]).reshape(-1, 1)).to(device)
done = torch.FloatTensor(np.array(samples["done"]).reshape(-1, 1)).to(device)
# Categorical DQN algorithm
delta_z = float(self.v_max - self.v_min) / (self.atom_size - 1)
with torch.no_grad():
# Double DQN
next_action = self.dqn(next_state).argmax(1)
next_dist = self.dqn_target.dist(next_state)
next_dist = next_dist[range(self.batch_size), next_action]
t_z = reward + (1 - done) * gamma * self.support
t_z = t_z.clamp(min=self.v_min, max=self.v_max)
b = (t_z - self.v_min) / delta_z
l = b.floor().long()
u = b.ceil().long()
offset = (
torch.linspace(
0, (self.batch_size - 1) * self.atom_size, self.batch_size
).long()
.unsqueeze(1)
.expand(self.batch_size, self.atom_size)
.to(self.device)
)
proj_dist = torch.zeros(next_dist.size(), device=self.device)
proj_dist.view(-1).index_add_(
0, (l + offset).view(-1), (next_dist * (u.float() - b)).view(-1)
)
proj_dist.view(-1).index_add_(
0, (u + offset).view(-1), (next_dist * (b - l.float())).view(-1)
)
print(f"Next Action : {next_action}\n Next Dist : {next_dist}\n")
dist = self.dqn.dist(state)
log_p = torch.log(dist[range(self.batch_size), action])
elementwise_loss = -(proj_dist * log_p).sum(1)
print(f"Proj Dist : {proj_dist}\n Dist : {dist}\n Log_p : {log_p}\n")
if torch.isnan(elementwise_loss[0][0]):
exit()
return elementwise_loss
def _target_hard_update(self,loss):
"""Hard update: target <- local."""
self.dqn_target.load_state_dict(self.dqn.state_dict())
#torch.save(self.dqn.state_dict(),str("checkpoint_"+str(time.time())))
torch.save({
'model_state_dict': self.dqn.state_dict(),
'optimizer_state_dict': self.optimizer.state_dict(),
'loss': loss,
}, str("checkpoints/checkpoint_"+str(time.time())))
nstep = 3
# nstep = False
if nstep:
Nstep = {"size": nstep, "rew": "rew", "next": "next_obs"}
discount = tf.constant(gamma**nstep)
else:
Nstep = None
discount = tf.constant(gamma)
# Prioritized Experience Replay: https://arxiv.org/abs/1511.05952
# See https://ymd_h.gitlab.io/cpprb/features/per/
prioritized = True
if prioritized:
rb = PrioritizedReplayBuffer(buffer_size, env_dict, Nstep=Nstep)
# Beta linear annealing
beta = 0.4
beta_step = (1 - beta) / N_iteration
else:
rb = ReplayBuffer(buffer_size, env_dict, Nstep=Nstep)
@tf.function
def Q_func(model, obs, act, act_shape):
return tf.reduce_sum(model(obs) * tf.one_hot(act, depth=act_shape), axis=1)
@tf.function
def DQN_target_func(model, target, next_obs, rew, done, gamma, act_shape):
},
"act": {
"shape": act_shape
},
"next_obs": {
"shape": obs_shape
},
"rew": {},
"done": {}
}
# Initialize Replay Buffer
rb = RB(buffer_size, env_dict)
# Initialize Prioritized Replay Buffer
prb = PRB(buffer_size, env_dict, alpha=alpha)
# Initalize Reverb Server
server = reverb.Server(tables=[
reverb.Table(name='ReplayBuffer',
sampler=reverb.selectors.Uniform(),
remover=reverb.selectors.Fifo(),
max_size=buffer_size,
rate_limiter=reverb.rate_limiters.MinSize(1)),
reverb.Table(name='PrioritizedReplayBuffer',
sampler=reverb.selectors.Prioritized(alpha),
remover=reverb.selectors.Fifo(),
max_size=buffer_size,
rate_limiter=reverb.rate_limiters.MinSize(1))
])
eps_tracker = ptan.actions.EpsilonTracker(
selector, params.eps_start, params.eps_final, params.eps_frames*args.envs)
agent = ptan.agent.DQNAgent(net, selector, device=device)
exp_source = ptan.experience.ExperienceSourceFirstLast(
envs, agent, params.gamma, steps_count=args.steps)
env_dict = {'state': {'shape': shape, 'dtype': np.uint8},
'action': {'dtype': np.int8},
'reward': {},
'last_state': {'shape': shape, 'dtype': np.uint8},
'done': {'dtype': np.bool}
}
step = (TGT_BETA - BETA)/END_BETA_FRAME
buffer = PrioritizedReplayBuffer(params.buffer_size, env_dict) if args.priority else \
ReplayBuffer(params.buffer_size, env_dict=env_dict)
folder, sub_folder, log_dir = utils.writerDir(envs[0], args.steps)
comment = "".join(
[envs[0].game, '_', str(args.steps), '_', str(args.envs)])
writer = SummaryWriter(comment=comment)
optimizer = torch.optim.Adam(net.parameters(), lr=params.lr)
scheduler = torch.optim.lr_scheduler.ReduceLROnPlateau(optimizer, mode='max', factor=0.75, patience=20000,
cooldown=20000, verbose=True, min_lr=params.min_lr)
mean = None
best_reward = -float('inf')
st = datetime.now()
print(net)
class ReplayMemory():
def __init__(self, args, capacity, env):
# Initial importance sampling weight β, annealed to 1 over course of training
self.priority_weight = args.priority_weight
self.n = args.multi_step
self.device = args.device
if args.mmap:
os.makedirs('memories/', exist_ok=True)
mmap_prefix = 'memories/mm'
else:
mmap_prefix = None
self.buffer = PrioritizedReplayBuffer(
capacity,
{
"obs": {
"shape": env.observation_space.shape,
"dtype": env.observation_space.dtype
},
"next_obs": {
"shape": env.observation_space.shape,
"dtype": env.observation_space.dtype
},
"act": {
"shape": 1,
"dtype": env.action_space.dtype
},
"rew": {
"dtype": np.float32
},
"done": {
"dtype": np.uint8
},
},
Nstep={
"size": self.n,
"gamma": args.discount,
"rew": "rew",
"next": "next_obs",
},
mmap_prefix=mmap_prefix,
alpha=args.priority_exponent,
# next_of="obs",
# stack_compress="obs",
)
def append(self, state, next_state, action, reward, done):
self.buffer.add(
**{
"obs": state,
"next_obs": next_state,
"act": action,
"rew": reward,
"done": done,
})
def sample(self, size):
s = self.buffer.sample(size, self.priority_weight)
s['indexes'] = s['indexes'].astype(np.int32)
return torchify((s['indexes'], torch.int32), (s['obs'], torch.float32),
(np.squeeze(s['act'], 1), torch.long),
(np.squeeze(s['rew'], 1), torch.float32),
(s['next_obs'], torch.float32),
(s['done'], torch.bool), (s['weights'], torch.float32),
device=self.device)
def update_priorities(self, indexes, new_priorities):
indexes = indexes.cpu().numpy()
self.buffer.update_priorities(indexes, new_priorities)
def __init__(
self,
env: gym.Env,
memory_size: int,
batch_size: int,
target_update: int,
gamma: float = 0.99,
# PER parameters
alpha: float = 0.2,
beta: float = 0.6,
prior_eps: float = 1e-6,
# Categorical DQN parameters
v_min: float = 0.0,
v_max: float = 200.0,
atom_size: int = 51,
# N-step Learning
n_step: int = 3,
# Convergence parameters
convergence_window: int = 100,
convergence_window_epsilon_p: int = 10,
convergence_avg_score: float = 195.0,
convergence_avg_epsilon: float = 0.0524, # 3 degs converted to rads
convergence_avg_epsilon_p: float = 0.0174, # 1 deg/s converted to rad/s
# Tensorboard parameters
model_name: str = "snake_joint",
):
"""Initialization.
Args:
env (gym.Env): openAI Gym environment
memory_size (int): length of memory
batch_size (int): batch size for sampling
target_update (int): period for target model's hard update
lr (float): learning rate
gamma (float): discount factor
alpha (float): determines how much prioritization is used
beta (float): determines how much importance sampling is used
prior_eps (float): guarantees every transition can be sampled
v_min (float): min value of support
v_max (float): max value of support
atom_size (int): the unit number of support
n_step (int): step number to calculate n-step td error
"""
obs_dim = env.observation_space.shape[0]
action_dim = env.action_space.n
self.env = env
self.batch_size = batch_size
self.target_update = target_update
self.gamma = gamma
# NoisyNet: All attributes related to epsilon are removed
#produces a unique timestamp for each run
run_timestamp=str(
#returns number of day and number of month
str(time.localtime(time.time())[2]) + "_" +
str(time.localtime(time.time())[1]) + "_" +
#returns hour, minute and second
str(time.localtime(time.time())[3]) + "_" +
str(time.localtime(time.time())[4]) + "_" +
str(time.localtime(time.time())[5])
)
#Will write scalars that can be visualized using tensorboard in the directory "runLogs/timestamp"
self.writer = SummaryWriter("runLogs/" + run_timestamp)
# device: cpu / gpu
self.device = torch.device(
"cuda" if torch.cuda.is_available() else "cpu"
)
print(self.device)
# PER
# memory for 1-step Learning
self.beta = beta
self.prior_eps = prior_eps
self.memory = PrioritizedReplayBuffer(
memory_size,
{
"obs": {"shape": (obs_dim,)},
"act": {"shape": (1,)},
"rew": {},
"next_obs": {"shape": (obs_dim,)},
"done": {}
},
alpha=alpha
)
# memory for N-step Learning
self.use_n_step = True if n_step > 1 else False
if self.use_n_step:
self.n_step = n_step
self.memory_n = ReplayBuffer(
memory_size,
{
"obs": {"shape": (obs_dim,)},
"act": {"shape": (1,)},
"rew": {},
"next_obs": {"shape": (obs_dim,)},
"done": {}
},
Nstep={
"size": n_step,
"gamma": gamma,
"rew": "rew",
"next": "next_obs"
}
)
# Categorical DQN parameters
self.v_min = v_min
self.v_max = v_max
self.atom_size = atom_size
self.support = torch.linspace(
self.v_min, self.v_max, self.atom_size
).to(self.device)
# networks: dqn, dqn_target
self.dqn = Network(
obs_dim, action_dim, self.atom_size, self.support
).to(self.device)
self.dqn_target = Network(
obs_dim, action_dim, self.atom_size, self.support
).to(self.device)
self.dqn_target.load_state_dict(self.dqn.state_dict())
self.dqn_target.eval()
# optimizer
self.optimizer = optim.Adam(self.dqn.parameters(),0.0001)
# transition to store in memory
self.transition = list()
# mode: train / test
self.is_test = False
# Custom tensorboard object
# self.tensorboard = RainbowTensorBoard(
# log_dir="single_joint_logs/{}-{}".format(
# model_name,
# datetime.now().strftime("%m-%d-%Y-%H_%M_%S")
# )
# )
# Convergence criterion
self.convergence_window = convergence_window
self.convergence_window_epsilon_p = convergence_window_epsilon_p
self.convergence_avg_score = convergence_avg_score
self.convergence_avg_epsilon = convergence_avg_epsilon
self.convergence_avg_epsilon_p = convergence_avg_epsilon_p
class Agent:
def __init__(self,
lr,
state_shape,
num_actions,
batch_size,
max_mem_size=100000):
self.lr = lr
self.gamma = 0.99
self.action_space = list(range(num_actions))
self.batch_size = batch_size
self.epsilon = Lerper(start=1.0, end=0.01, num_steps=2000)
self.importance_exp = Lerper(start=0.4, end=1.0, num_steps=100000)
self.priority_exp = 0.6
self.memory = PrioritizedReplayBuffer(max_mem_size, {
"obs": {
"shape": state_shape
},
"act": {
"shape": 1
},
"rew": {},
"next_obs": {
"shape": state_shape
},
"done": {
"shape": 1
}
},
alpha=self.priority_exp)
self.net = Network(lr, state_shape, num_actions)
def choose_action(self, observation):
if np.random.random() > self.epsilon.value():
state = torch.tensor(observation).float().detach()
state = state.to(self.net.device)
state = state.unsqueeze(0)
q_values = self.net(state)
action = torch.argmax(q_values).item()
return action
else:
return np.random.choice(self.action_space)
def store_memory(self, state, action, reward, next_state, done):
self.memory.add(obs=state,
act=action,
rew=reward,
next_obs=next_state,
done=done)
def learn(self):
if self.memory.get_stored_size() < self.batch_size:
return
batch = self.memory.sample(self.batch_size,
self.importance_exp.value())
states = torch.tensor(batch["obs"]).to(self.net.device)
actions = torch.tensor(batch["act"],
dtype=torch.int64).to(self.net.device).T[0]
rewards = torch.tensor(batch["rew"]).to(self.net.device).T[0]
states_ = torch.tensor(batch["next_obs"]).to(self.net.device)
dones = torch.tensor(batch["done"],
dtype=torch.bool).to(self.net.device).T[0]
weights = torch.tensor(batch["weights"]).to(self.net.device)
batch_index = np.arange(self.batch_size, dtype=np.int64)
q_values = self.net(states)[batch_index, actions]
q_values_ = self.net(states_)
action_qs_ = torch.max(q_values_, dim=1)[0]
action_qs_[dones] = 0.0
q_target = rewards + self.gamma * action_qs_
td = q_target - q_values
self.net.optimizer.zero_grad()
loss = ((td**2.0) * weights).mean()
loss.backward()
self.net.optimizer.step()
new_priorities = (td.abs()).detach().cpu()
self.memory.update_priorities(batch["indexes"], new_priorities)
self.epsilon.step()
self.importance_exp.step()
"done": {}
}
# Initialize Replay Buffer
brb = bRB(buffer_size)
rrb = rRB(buffer_size)
rrb._num_sampled = 0 # Fix: https://github.com/ray-project/ray/issues/14818
crb = cRB(buffer_size)
rb = RB(buffer_size, env_dict)
# Initialize Prioritized Replay Buffer
bprb = bPRB(buffer_size, alpha=alpha)
rprb = rPRB(buffer_size, alpha=alpha)
cprb = cPRB(buffer_size, alpha=alpha, beta0=beta, betasteps=None)
prb = PRB(buffer_size, env_dict, alpha=alpha)
# Helper Function
def env(n):
e = {
"obs": np.ones((n, obs_shape)),
"act": np.zeros((n, act_shape)),
"next_obs": np.ones((n, obs_shape)),
"rew": np.zeros(n),
"done": np.zeros(n)
}
return e
def add_b(_rb):
def test_raise_imcompatible_priority_shape(self):
rb = PrioritizedReplayBuffer(32, env_dict={'a': {'shape': 1}})
with self.assertRaises(ValueError):
rb.add(a=np.ones(5), priorities=np.ones(3))