def ppo(env_fn,
actor_critic=core.mlp_actor_critic,
ac_kwargs=dict(),
seed=0,
batch_size=250000,
n=100,
epochs=100,
gamma=0.99,
clip_ratio=0.2,
pi_lr=3e-4,
vf_lr=1e-3,
train_pi_iters=1000,
train_v_iters=80,
lam=0.97,
max_ep_len=1000,
target_kl=0.01,
logger_kwargs=dict(),
save_freq=10):
"""
Args:
env_fn : A function which creates a copy of the environment.
The environment must satisfy the OpenAI Gym API.
actor_critic: A function which takes in placeholder symbols
for state, ``x_ph``, and action, ``a_ph``, and returns the main
outputs from the agent's Tensorflow computation graph:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``pi`` (batch, act_dim) | Samples actions from policy given
| states.
``logp`` (batch,) | Gives log probability, according to
| the policy, of taking actions ``a_ph``
| in states ``x_ph``.
``logp_pi`` (batch,) | Gives log probability, according to
| the policy, of the action sampled by
| ``pi``.
``v`` (batch,) | Gives the value estimate for states
| in ``x_ph``. (Critical: make sure
| to flatten this!)
=========== ================ ======================================
ac_kwargs (dict): Any kwargs appropriate for the actor_critic
function you provided to PPO.
seed (int): Seed for random number generators.
steps_per_epoch (int): Number of steps of interaction (state-action pairs)
for the agent and the environment in each epoch.
epochs (int): Number of epochs of interaction (equivalent to
number of policy updates) to perform.
gamma (float): Discount factor. (Always between 0 and 1.)
clip_ratio (float): Hyperparameter for clipping in the policy objective.
Roughly: how far can the new policy go from the old policy while
still profiting (improving the objective function)? The new policy
can still go farther than the clip_ratio says, but it doesn't help
on the objective anymore. (Usually small, 0.1 to 0.3.)
pi_lr (float): Learning rate for policy optimizer.
vf_lr (float): Learning rate for value function optimizer.
train_pi_iters (int): Maximum number of gradient descent steps to take
on policy loss per epoch. (Early stopping may cause optimizer
to take fewer than this.)
train_v_iters (int): Number of gradient descent steps to take on
value function per epoch.
lam (float): Lambda for GAE-Lambda. (Always between 0 and 1,
close to 1.)
max_ep_len (int): Maximum length of trajectory / episode / rollout.
target_kl (float): Roughly what KL divergence we think is appropriate
between new and old policies after an update. This will get used
for early stopping. (Usually small, 0.01 or 0.05.)
logger_kwargs (dict): Keyword args for EpochLogger.
save_freq (int): How often (in terms of gap between epochs) to save
the current policy and value function.
"""
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
tf.set_random_seed(seed)
np.random.seed(seed)
env = env_fn()
obs_dim = env.observation_space.shape
act_dim = env.action_space.shape
sequence_length = n * max_ep_len
trials = batch_size // sequence_length
# Share information about action space with policy architecture
ac_kwargs['action_space'] = env.action_space
# Inputs to computation graph
# x_ph, a_ph = core.placeholders_from_spaces(env.observation_space, env.action_space)
# rew_ph, adv_ph, ret_ph, logp_old_ph = core.placeholders(1, None, None, None)
x_ph = tf.placeholder(dtype=tf.int32,
shape=(None, sequence_length),
name='x_ph')
t_ph = tf.placeholder(dtype=tf.int32,
shape=(None, sequence_length),
name='t_ph')
a_ph = tf.placeholder(dtype=tf.int32,
shape=(None, sequence_length),
name='a_ph')
r_ph = tf.placeholder(dtype=tf.float32,
shape=(None, sequence_length),
name='r_ph')
# input_ph = tf.placeholder(dtype=tf.float32, shape=(None, None, n, None), name='rew_ph')
adv_ph = tf.placeholder(dtype=tf.float32, shape=(None), name='adv_ph')
ret_ph = tf.placeholder(dtype=tf.float32, shape=(None), name='ret_ph')
logp_old_ph = tf.placeholder(dtype=tf.float32,
shape=(None),
name='logp_old_ph')
# Main outputs from computation graph
pi, logp, logp_pi, v = actor_critic(x_ph, t_ph, a_ph, r_ph,
sequence_length, env.action_space.n,
env.observation_space.shape[0])
# Need all placeholders in *this* order later (to zip with data from buffer)
all_phs = [x_ph, t_ph, a_ph, r_ph, adv_ph, ret_ph, logp_old_ph]
# for ph in all_phs:
# print(ph.shape)
# Every step, get: action, value, and logprob
get_action_ops = [pi, v, logp_pi]
# Experience buffer
buf = PPOBuffer(obs_dim, act_dim, batch_size, gamma, lam)
# Count variables
var_counts = tuple(core.count_vars(scope) for scope in ['pi', 'v'])
logger.log('\nNumber of parameters: \t pi: %d, \t v: %d\n' % var_counts)
# PPO objectives
ratio = tf.exp(logp - logp_old_ph) # pi(a|s) / pi_old(a|s)
min_adv = tf.where(adv_ph > 0, (1 + clip_ratio) * adv_ph,
(1 - clip_ratio) * adv_ph)
pi_loss = -tf.reduce_mean(tf.minimum(ratio * adv_ph, min_adv))
v_loss = tf.reduce_mean((ret_ph - v)**2)
# Info (useful to watch during learning)
approx_kl = tf.reduce_mean(
logp_old_ph -
logp) # a sample estimate for KL-divergence, easy to compute
approx_ent = tf.reduce_mean(
-logp) # a sample estimate for entropy, also easy to compute
clipped = tf.logical_or(ratio > (1 + clip_ratio), ratio < (1 - clip_ratio))
clipfrac = tf.reduce_mean(tf.cast(clipped, tf.float32))
# Optimizers
train_pi = MpiAdamOptimizer(learning_rate=pi_lr).minimize(pi_loss)
train_v = MpiAdamOptimizer(learning_rate=vf_lr).minimize(v_loss)
sess = tf.Session()
sess.run(tf.global_variables_initializer())
# Sync params across processes
sess.run(sync_all_params())
# Setup model saving
model_inputs = {'x': x_ph, 't': t_ph, 'a': a_ph, 'r': r_ph}
model_outputs = {'pi': pi}
logger.setup_tf_saver(sess, inputs=model_inputs, outputs=model_outputs)
def update():
inputs = {k: v for k, v in zip(all_phs, buf.get())}
# inputs[a_ph] = np.tril(np.transpose(np.repeat(inputs[a_ph], n).reshape(trials, n, n), [0, 2, 1]))
# inputs[rew_ph] = np.tril(np.transpose(np.repeat(inputs[rew_ph], n).reshape(trials, n, n), [0, 2, 1]))
# print(inputs[x_ph])
# print(inputs[t_ph])
# print(inputs[a_ph])
# print(inputs[r_ph])
inputs[x_ph] = inputs[x_ph].reshape(trials, sequence_length)
inputs[t_ph] = inputs[t_ph].reshape(trials, sequence_length)
inputs[a_ph] = inputs[a_ph].reshape(trials, sequence_length)
inputs[r_ph] = inputs[r_ph].reshape(trials, sequence_length)
# print('x:', inputs[x_ph])
# print('t:', inputs[t_ph])
# print('a:', inputs[a_ph])
# print('r:', inputs[r_ph])
# print('ret:', inputs[ret_ph])
# print('adv:', inputs[adv_ph])
# print('logp_old:', inputs[logp_old_ph])
pi_l_old, v_l_old, ent = sess.run([pi_loss, v_loss, approx_ent],
feed_dict=inputs)
# Training
for i in range(train_pi_iters):
_, kl = sess.run([train_pi, approx_kl], feed_dict=inputs)
# kl = mpi_avg(kl)
# if kl > 1.5 * target_kl:
# logger.log('Early stopping at step %d due to reaching max kl.'%i)
# break
logger.store(StopIter=i)
for _ in range(train_v_iters):
sess.run(train_v, feed_dict=inputs)
# Log changes from update
pi_l_new, v_l_new, kl, cf = sess.run(
[pi_loss, v_loss, approx_kl, clipfrac], feed_dict=inputs)
logger.store(LossPi=pi_l_old,
LossV=v_l_old,
KL=kl,
Entropy=ent,
ClipFrac=cf,
DeltaLossPi=(pi_l_new - pi_l_old),
DeltaLossV=(v_l_new - v_l_old))
start_time = time.time()
save_itr = 0
# Main loop: collect experience in env and update/log each epoch
for epoch in range(epochs):
for trail in range(trials):
print('trial:', trail)
# last_a = np.zeros(n).reshape(1, n)
# last_r = np.zeros(n).reshape(1, n)
o_deque = deque(sequence_length * [0], sequence_length)
t_deque = deque(sequence_length * [0], sequence_length)
last_a = deque(sequence_length * [0], sequence_length)
last_r = deque(sequence_length * [0], sequence_length)
means = env.sample_tasks(1)[0]
# print('task means:', means)
action_dict = defaultdict(int)
total_reward = 0
env.reset_task(means)
o, r, d, ep_ret, ep_len = env.reset(), np.zeros(1), False, 0, 0
for episode in range(sequence_length):
# print('episode:', episode)
# print('o:', o_deque)
# print('d:', t_deque)
# print('a:', last_a)
# print('r:', last_r)
a, v_t, logp_t = sess.run(
get_action_ops,
feed_dict={
x_ph: np.array(o_deque).reshape(1, sequence_length),
t_ph: np.array(t_deque).reshape(1, sequence_length),
a_ph: np.array(last_a).reshape(1, sequence_length),
r_ph: np.array(last_r).reshape(1, sequence_length)
})
# print("a shape:", a.shape)
# print("v_t shape:", v_t.shape)
# print("logp_t shape:", logp_t.shape)
# choosen_a = a[episode, 0]
# choosen_v_t = v_t[0, episode]
# choosen_logp_t = logp_t[episode]
# print('a:', a)
choosen_a = a[-1]
choosen_v_t = v_t[-1]
choosen_logp_t = logp_t[-1]
action_dict[choosen_a] += 1
o, r, d, _ = env.step(choosen_a)
ep_ret += r
ep_len += 1
t = ep_len == max_ep_len
total_reward += r
o_deque.append(o)
t_deque.append(int(d))
last_a.append(choosen_a)
last_r.append(r)
# save and log
buf.store(o, int(t), choosen_a, r, choosen_v_t, choosen_logp_t)
logger.store(VVals=v_t)
terminal = d or t
if terminal or (episode == sequence_length - 1):
if not (terminal):
print(
'Warning: trajectory cut off by epoch at %d steps.'
% ep_len)
# if trajectory didn't reach terminal state, bootstrap value target
if d:
last_val = r
else:
last_val = sess.run(
v,
feed_dict={
x_ph:
np.array(o_deque).reshape(1, sequence_length),
t_ph:
np.array(t_deque).reshape(1, sequence_length),
a_ph:
np.array(last_a).reshape(1, sequence_length),
r_ph:
np.array(last_r).reshape(1, sequence_length)
})
last_val = last_val[-1]
buf.finish_path(last_val)
if terminal:
# only save EpRet / EpLen if trajectory finished
logger.store(EpRet=ep_ret, EpLen=ep_len)
o, r, d, ep_ret, ep_len = env.reset(), 0, False, 0, 0
o_deque[-1] = 0
t_deque[-1] = 0
last_a[-1] = 0
last_r[-1] = 0
print(action_dict)
print('average reward:', total_reward / sequence_length)
# Save model
if (epoch % save_freq == 0) or (epoch == epochs - 1):
logger.save_state({'env': env}, save_itr)
save_itr += 1
# Perform PPO update!
update()
# Log info about epoch
logger.log_tabular('Epoch', epoch)
logger.log_tabular('EpRet', with_min_and_max=True)
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('VVals', with_min_and_max=True)
logger.log_tabular('TotalEnvInteracts', (epoch + 1) * batch_size)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('LossV', average_only=True)
logger.log_tabular('DeltaLossPi', average_only=True)
logger.log_tabular('DeltaLossV', average_only=True)
logger.log_tabular('Entropy', average_only=True)
logger.log_tabular('KL', average_only=True)
logger.log_tabular('ClipFrac', average_only=True)
logger.log_tabular('StopIter', average_only=True)
logger.log_tabular('Time', time.time() - start_time)
logger.dump_tabular()
def ppo(env_fn, actor_critic=core.mlp_actor_critic, ac_kwargs=dict(), seed=0, gru_units=256,
trials_per_epoch=100, episodes_per_trial=2, n = 100, epochs=100, gamma=0.99, clip_ratio=0.2, pi_lr=3e-4,
vf_lr=1e-3, train_pi_iters=1000, train_v_iters=80, lam=0.97, max_ep_len=1000,
target_kl=0.01, logger_kwargs=dict(), save_freq=10):
"""
Args:
env_fn : A function which creates a copy of the environment.
The environment must satisfy the OpenAI Gym API.
actor_critic: A function which takes in placeholder symbols
for state, ``x_ph``, and action, ``a_ph``, and returns the main
outputs from the agent's Tensorflow computation graph:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``pi`` (batch, act_dim) | Samples actions from policy given
| states.
``logp`` (batch,) | Gives log probability, according to
| the policy, of taking actions ``a_ph``
| in states ``x_ph``.
``logp_pi`` (batch,) | Gives log probability, according to
| the policy, of the action sampled by
| ``pi``.
``v`` (batch,) | Gives the value estimate for states
| in ``x_ph``. (Critical: make sure
| to flatten this!)
=========== ================ ======================================
ac_kwargs (dict): Any kwargs appropriate for the actor_critic
function you provided to PPO.
seed (int): Seed for random number generators.
steps_per_epoch (int): Number of steps of interaction (state-action pairs)
for the agent and the environment in each epoch.
epochs (int): Number of epochs of interaction (equivalent to
number of policy updates) to perform.
gamma (float): Discount factor. (Always between 0 and 1.)
clip_ratio (float): Hyperparameter for clipping in the policy objective.
Roughly: how far can the new policy go from the old policy while
still profiting (improving the objective function)? The new policy
can still go farther than the clip_ratio says, but it doesn't help
on the objective anymore. (Usually small, 0.1 to 0.3.)
pi_lr (float): Learning rate for policy optimizer.
vf_lr (float): Learning rate for value function optimizer.
train_pi_iters (int): Maximum number of gradient descent steps to take
on policy loss per epoch. (Early stopping may cause optimizer
to take fewer than this.)
train_v_iters (int): Number of gradient descent steps to take on
value function per epoch.
lam (float): Lambda for GAE-Lambda. (Always between 0 and 1,
close to 1.)
max_ep_len (int): Maximum length of trajectory / episode / rollout.
target_kl (float): Roughly what KL divergence we think is appropriate
between new and old policies after an update. This will get used
for early stopping. (Usually small, 0.01 or 0.05.)
logger_kwargs (dict): Keyword args for EpochLogger.
save_freq (int): How often (in terms of gap between epochs) to save
the current policy and value function.
"""
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
tf.set_random_seed(seed)
np.random.seed(seed)
env = env_fn()
obs_dim = env.observation_space.shape
act_dim = env.action_space.shape
# Share information about action space with policy architecture
ac_kwargs['action_space'] = env.action_space
# Inputs to computation graph\
raw_input_ph = tf.placeholder(dtype=tf.float32, shape=obs_dim, name='raw_input_ph')
rescale_image_op = tf.image.resize_images(raw_input_ph, [30, 40])
max_seq_len_ph = tf.placeholder(dtype=tf.int32, shape=(), name='max_seq_len_ph')
seq_len_ph = tf.placeholder(dtype=tf.int32, shape=(None,))
# Because we pad zeros at the end of every sequence of length less than max length, we need to mask these zeros out
# when computing loss
seq_len_mask_ph = tf.placeholder(dtype=tf.int32, shape=(trials_per_epoch, episodes_per_trial * max_ep_len))
# rescaled_image_ph This is a ph because we want to be able to pass in value to this node manually
rescaled_image_in_ph = tf.placeholder(dtype=tf.float32, shape=[None, 30, 40, 3], name='rescaled_image_in_ph')
a_ph = core.placeholders_from_spaces( env.action_space)[0]
conv1 = slim.conv2d(activation_fn=tf.nn.relu, inputs=rescaled_image_in_ph, num_outputs=16, kernel_size=[5,5],
stride=2)
image_out = slim.flatten(slim.conv2d(activation_fn=tf.nn.relu, inputs=conv1, num_outputs=16, kernel_size=[5,5],
stride=2))
rew_ph, adv_ph, ret_ph, logp_old_ph = core.placeholders(1, None, None, None)
rnn_state_ph = tf.placeholder(tf.float32, [None, gru_units], name='pi_rnn_state_ph')
# Main outputs from computation graph
action_encoder_matrix = np.load(r'encoder.npy')
pi, logp, logp_pi, v, rnn_state, logits, seq_len_vec, tmp_vec = actor_critic(
image_out, a_ph, rew_ph, rnn_state_ph, gru_units,
max_seq_len_ph, action_encoder_matrix, seq_len=seq_len_ph, action_space=env.action_space)
# Need all placeholders in *this* order later (to zip with data from buffer)
all_phs = [rescaled_image_in_ph, a_ph, adv_ph, ret_ph, logp_old_ph, rew_ph]
# Every step, get: action, value, and logprob
get_action_ops = [pi, v, logp_pi, rnn_state, logits]
# Experience buffer
buffer_size = trials_per_epoch * episodes_per_trial * max_ep_len
buf = PPOBuffer(rescaled_image_in_ph.get_shape().as_list()[1:], act_dim, buffer_size, trials_per_epoch, gamma, lam)
# Count variables
var_counts = tuple(core.count_vars(scope) for scope in ['pi', 'v'])
logger.log('\nNumber of parameters: \t pi: %d, \t v: %d\n'%var_counts)
# PPO objectives
ratio = tf.exp(logp - logp_old_ph) # pi(a|s) / pi_old(a|s)
min_adv = tf.where(adv_ph>0, (1+clip_ratio)*adv_ph, (1-clip_ratio)*adv_ph)
# Need to mask out the padded zeros when computing loss
sequence_mask = tf.sequence_mask(seq_len_ph, episodes_per_trial*max_ep_len)
# Convert bool tensor to int tensor with 1 and 0
sequence_mask = tf.where(sequence_mask,
np.ones(dtype=np.float32, shape=(trials_per_epoch, episodes_per_trial*max_ep_len)),
np.zeros(dtype=np.float32, shape=(trials_per_epoch, episodes_per_trial*max_ep_len)))
# need to reshape because ratio is a 1-D vector (it is a concatnation of all sequence) for masking and then reshape
# it back
pi_loss_vec = tf.multiply(sequence_mask, tf.reshape(tf.minimum(ratio * adv_ph, min_adv), tf.shape(sequence_mask)))
pi_loss = -tf.reduce_mean(tf.reshape(pi_loss_vec, tf.shape(ratio)))
aaa = (ret_ph - v)**2
v_loss_vec = tf.multiply(sequence_mask, tf.reshape((ret_ph - v)**2, tf.shape(sequence_mask)))
ccc = tf.reshape(v_loss_vec, tf.shape(v))
v_loss = tf.reduce_mean(tf.reshape(v_loss_vec, tf.shape(v)))
# Info (useful to watch during learning)
approx_kl = tf.reduce_mean(logp_old_ph - logp) # a sample estimate for KL-divergence, easy to compute
approx_ent = tf.reduce_mean(-logp) # a sample estimate for entropy, also easy to compute
clipped = tf.logical_or(ratio > (1+clip_ratio), ratio < (1-clip_ratio))
clipfrac = tf.reduce_mean(tf.cast(clipped, tf.float32))
# Optimizers
train_pi = MpiAdamOptimizer(learning_rate=pi_lr).minimize(pi_loss)
train_v = MpiAdamOptimizer(learning_rate=vf_lr).minimize(v_loss)
train = MpiAdamOptimizer(learning_rate=1e-4).minimize(pi_loss + 0.01 * v_loss - 0.001 * approx_ent)
sess = tf.Session()
sess.run(tf.global_variables_initializer())
# Sync params across processes
sess.run(sync_all_params())
# Setup model saving
logger.setup_tf_saver(sess, inputs={'rescaled_image_in': rescaled_image_in_ph}, outputs={'pi': pi, 'v': v})
def update():
print(f'Start updating at {datetime.now()}')
inputs = {k:v for k,v in zip(all_phs, buf.get())}
inputs[rnn_state_ph] = np.zeros((trials_per_epoch, gru_units), np.float32)
inputs[max_seq_len_ph] = int(episodes_per_trial * max_ep_len)
inputs[seq_len_ph] = buf.seq_len_buf
pi_l_old, v_l_old, ent = sess.run([pi_loss, v_loss, approx_ent], feed_dict=inputs)
buf.reset()
# Training
print(f'sequence length = {sess.run(seq_len_vec, feed_dict=inputs)}')
for i in range(train_pi_iters):
_, kl, pi_loss_i, v_loss_i, ent = sess.run([train_pi, approx_kl, pi_loss, v_loss, approx_ent], feed_dict=inputs)
print(f'i: {i}, pi_loss: {pi_loss_i}, v_loss: {v_loss_i}, entropy: {ent}')
logger.store(StopIter=i)
# Log changes from update
pi_l_new, v_l_new, kl, cf = sess.run(
[pi_loss, v_loss, approx_kl, clipfrac], feed_dict=inputs)
logger.store(LossPi=pi_l_old, LossV=v_l_old,
KL=kl, Entropy=ent, ClipFrac=cf,
DeltaLossPi=(pi_l_new - pi_l_old),
DeltaLossV=(v_l_new - v_l_old))
print(f'Updating finished at {datetime.now()}')
start_time = time.time()
o, r, d, ep_ret, ep_len = env.reset(), np.zeros(1), False, 0, 0
def recenter_rgb(image, min=0.0, max=255.0):
'''
:param image:
:param min:
:param max:
:return: an image with rgb value re-centered to [-1, 1]
'''
mid = (min + max) / 2.0
return np.apply_along_axis(func1d=lambda x: (x - mid) / mid, axis=2, arr=image)
o_rescaled = recenter_rgb(sess.run(rescale_image_op, feed_dict={raw_input_ph: o}))
# Main loop: collect experience in env and update/log each epoch
for epoch in range(epochs):
for trial in range(trials_per_epoch):
# TODO: tweek settings to match the paper
# TODO: find a way to generate mazes
last_a = np.array(0)
last_r = np.array(r)
last_rnn_state = np.zeros((1, gru_units), np.float32)
step_counter = 0
for episode in range(episodes_per_trial):
o, r, d, ep_ret, ep_len = env.reset(), 0, False, 0, 0
o_rescaled = recenter_rgb(sess.run(rescale_image_op, feed_dict={raw_input_ph: o}))
action_dict = defaultdict(int)
# dirty hard coding to make it print in order
action_dict[0] = 0
action_dict[1] = 0
action_dict[2] = 0
for step in range(max_ep_len):
a, v_t, logp_t, rnn_state_t, logits_t = sess.run(
get_action_ops, feed_dict={
rescaled_image_in_ph: np.expand_dims(o_rescaled, 0),
a_ph: last_a.reshape(-1,),
rew_ph: last_r.reshape(-1,1),
rnn_state_ph: last_rnn_state,
# v_rnn_state_ph: last_v_rnn_state,
max_seq_len_ph: 1,
seq_len_ph: [1]})
action_dict[a[0]] += 1
# save and log
buf.store(o_rescaled, a, r, v_t, logp_t)
logger.store(VVals=v_t)
o, r, d, _ = env.step(a[0])
step_counter += 1
o_rescaled = recenter_rgb(sess.run(rescale_image_op, feed_dict={raw_input_ph: o}))
ep_ret += r
ep_len += 1
last_a = a[0]
last_r = np.array(r)
last_rnn_state = rnn_state_t
terminal = d or (ep_len == max_ep_len)
if terminal or (step==n-1):
if not(terminal):
print('Warning: trajectory cut off by epoch at %d steps.'%ep_len)
# if trajectory didn't reach terminal state, bootstrap value target
last_val = r if d else sess.run(v, feed_dict={rescaled_image_in_ph: np.expand_dims(o_rescaled, 0),
a_ph: last_a.reshape(-1,),
rew_ph: last_r.reshape(-1,1),
rnn_state_ph: last_rnn_state,
max_seq_len_ph: 1,
seq_len_ph: [1]})
buf.finish_path(last_val)
logger.store(EpRet=ep_ret, EpLen=ep_len)
print(f'episode terminated with {step} steps. epoch:{epoch} trial:{trial} episode:{episode}')
break
print(action_dict)
if step_counter < episodes_per_trial * max_ep_len:
buf.pad_zeros(episodes_per_trial * max_ep_len - step_counter)
buf.seq_len_buf[trial] = step_counter
# pad zeros to sequence buffer after each trial
# Save model
if (epoch % save_freq == 0) or (epoch == epochs-1):
logger.save_state({'env': env}, None)
# Perform PPO update!
update()
# Log info about epoch
logger.log_tabular('Epoch', epoch)
logger.log_tabular('EpRet', with_min_and_max=True)
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('VVals', with_min_and_max=True)
logger.log_tabular('TotalEnvInteracts', (epoch+1)*trials_per_epoch*episodes_per_trial*max_ep_len)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('LossV', average_only=True)
logger.log_tabular('DeltaLossPi', average_only=True)
logger.log_tabular('DeltaLossV', average_only=True)
logger.log_tabular('Entropy', average_only=True)
logger.log_tabular('KL', average_only=True)
logger.log_tabular('ClipFrac', average_only=True)
logger.log_tabular('StopIter', average_only=True)
logger.log_tabular('Time', time.time()-start_time)
logger.dump_tabular()
def ppo(env_fn,
actor_critic=core.MLPActorCritic,
ac_kwargs=dict(),
seed=0,
steps_per_epoch=4000,
epochs=50,
gamma=0.99,
clip_ratio=0.2,
pi_lr=3e-4,
vf_lr=1e-3,
train_pi_iters=80,
train_v_iters=80,
lam=0.97,
max_ep_len=None,
target_kl=0.01,
logger_kwargs=dict(),
save_freq=10,
TensorBoard=True,
save_nn=True,
save_every=1000,
load_latest=False,
load_custom=False,
LoadPath=None,
RTA_type=None):
"""
Proximal Policy Optimization (by clipping),
with early stopping based on approximate KL
Args:
env_fn : A function which creates a copy of the environment.
The environment must satisfy the OpenAI Gym API.
actor_critic: The constructor method for a PyTorch Module with a
``step`` method, an ``act`` method, a ``pi`` module, and a ``v``
module. The ``step`` method should accept a batch of observations
and return:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``a`` (batch, act_dim) | Numpy array of actions for each
| observation.
``v`` (batch,) | Numpy array of value estimates
| for the provided observations.
``logp_a`` (batch,) | Numpy array of log probs for the
| actions in ``a``.
=========== ================ ======================================
The ``act`` method behaves the same as ``step`` but only returns ``a``.
The ``pi`` module's forward call should accept a batch of
observations and optionally a batch of actions, and return:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``pi`` N/A | Torch Distribution object, containing
| a batch of distributions describing
| the policy for the provided observations.
``logp_a`` (batch,) | Optional (only returned if batch of
| actions is given). Tensor containing
| the log probability, according to
| the policy, of the provided actions.
| If actions not given, will contain
| ``None``.
=========== ================ ======================================
The ``v`` module's forward call should accept a batch of observations
and return:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``v`` (batch,) | Tensor containing the value estimates
| for the provided observations. (Critical:
| make sure to flatten this!)
=========== ================ ======================================
ac_kwargs (dict): Any kwargs appropriate for the ActorCritic object
you provided to PPO.
seed (int): Seed for random number generators.
steps_per_epoch (int): Number of steps of interaction (state-action pairs)
for the agent and the environment in each epoch.
epochs (int): Number of epochs of interaction (equivalent to
number of policy updates) to perform.
gamma (float): Discount factor. (Always between 0 and 1.)
clip_ratio (float): Hyperparameter for clipping in the policy objective.
Roughly: how far can the new policy go from the old policy while
still profiting (improving the objective function)? The new policy
can still go farther than the clip_ratio says, but it doesn't help
on the objective anymore. (Usually small, 0.1 to 0.3.) Typically
denoted by :math:`\epsilon`.
pi_lr (float): Learning rate for policy optimizer.
vf_lr (float): Learning rate for value function optimizer.
train_pi_iters (int): Maximum number of gradient descent steps to take
on policy loss per epoch. (Early stopping may cause optimizer
to take fewer than this.)
train_v_iters (int): Number of gradient descent steps to take on
value function per epoch.
lam (float): Lambda for GAE-Lambda. (Always between 0 and 1,
close to 1.)
max_ep_len (int): Maximum length of trajectory / episode / rollout.
target_kl (float): Roughly what KL divergence we think is appropriate
between new and old policies after an update. This will get used
for early stopping. (Usually small, 0.01 or 0.05.)
logger_kwargs (dict): Keyword args for EpochLogger.
save_freq (int): How often (in terms of gap between epochs) to save
the current policy and value function.
TensorBoard (bool): True plots to TensorBoard, False does not
save_nn (bool): True saves neural network data, False does not
save_every (int): How often to save neural network
load_latest (bool): Load last saved neural network data before training
load_custom (bool): Load custom neural network data file before training
LoadPath (str): Path for custom neural network data file
RTA_type (str): RTA framework, either 'CBF', 'SVL', 'ASIF', or
'SBSF'
"""
# Special function to avoid certain slowdowns from PyTorch + MPI combo.
setup_pytorch_for_mpi()
# Set up logger and save configuration
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
# Instantiate environment
env = env_fn()
obs_dim = env.observation_space.shape
act_dim = env.action_space.shape
# Random seed for each cpu
seed += 1 * proc_id()
env.seed(seed)
# Create actor-critic module
ac = actor_critic(env.observation_space, env.action_space, **ac_kwargs)
# Load model if True
if load_latest:
models = glob.glob(f"{PATH}/models/PPO/*")
LoadPath = max(models, key=os.path.getctime)
ac.load_state_dict(torch.load(LoadPath))
elif load_custom:
ac.load_state_dict(torch.load(LoadPath))
# Sync params across processes
sync_params(ac)
# Count variables
var_counts = tuple(core.count_vars(module) for module in [ac.pi, ac.v])
logger.log('\nNumber of parameters: \t pi: %d, \t v: %d\n' % var_counts)
# Set up experience buffer
local_steps_per_epoch = int(steps_per_epoch / num_procs())
buf = PPOBuffer(obs_dim, act_dim, local_steps_per_epoch, gamma, lam)
# Set up function for computing PPO policy loss
def compute_loss_pi(data):
obs, act, adv, logp_old = data['obs'], data['act'], data['adv'], data[
'logp']
# Policy loss
pi, logp = ac.pi(obs, act)
ratio = torch.exp(logp - logp_old)
clip_adv = torch.clamp(ratio, 1 - clip_ratio, 1 + clip_ratio) * adv
loss_pi = -(torch.min(ratio * adv, clip_adv)).mean()
# Useful extra info
approx_kl = (logp_old - logp).mean().item()
ent = pi.entropy().mean().item()
clipped = ratio.gt(1 + clip_ratio) | ratio.lt(1 - clip_ratio)
clipfrac = torch.as_tensor(clipped, dtype=torch.float32).mean().item()
pi_info = dict(kl=approx_kl, ent=ent, cf=clipfrac)
return loss_pi, pi_info
# Set up function for computing value loss
def compute_loss_v(data):
obs, ret = data['obs'], data['ret']
return ((ac.v(obs) - ret)**2).mean()
# Set up optimizers for policy and value function
pi_optimizer = Adam(ac.pi.parameters(), lr=pi_lr)
vf_optimizer = Adam(ac.v.parameters(), lr=vf_lr)
# Set up model saving
logger.setup_pytorch_saver(ac)
def update():
data = buf.get()
pi_l_old, pi_info_old = compute_loss_pi(data)
pi_l_old = pi_l_old.item()
v_l_old = compute_loss_v(data).item()
# Train policy with multiple steps of gradient descent
for i in range(train_pi_iters):
pi_optimizer.zero_grad()
loss_pi, pi_info = compute_loss_pi(data)
kl = mpi_avg(pi_info['kl'])
if kl > 1.5 * target_kl:
logger.log(
'Early stopping at step %d due to reaching max kl.' % i)
break
loss_pi.backward()
mpi_avg_grads(ac.pi) # average grads across MPI processes
pi_optimizer.step()
logger.store(StopIter=i)
# Value function learning
for i in range(train_v_iters):
vf_optimizer.zero_grad()
loss_v = compute_loss_v(data)
loss_v.backward()
mpi_avg_grads(ac.v) # average grads across MPI processes
vf_optimizer.step()
# Log changes from update
kl, ent, cf = pi_info['kl'], pi_info_old['ent'], pi_info['cf']
logger.store(LossPi=pi_l_old,
LossV=v_l_old,
KL=kl,
Entropy=ent,
ClipFrac=cf,
DeltaLossPi=(loss_pi.item() - pi_l_old),
DeltaLossV=(loss_v.item() - v_l_old))
# Import RTA
if RTA_type == 'CBF':
from CBF_for_speed_limit import RTA
elif RTA_type == 'SVL':
from Simple_velocity_limit import RTA
elif RTA_type == 'ASIF':
from IASIF import RTA
elif RTA_type == 'SBSF':
from ISimplex import RTA
# Call RTA, define action conversion
if RTA_type != 'off':
env.RTA_reward = RTA_type
rta = RTA(env)
def RTA_act(obs, act):
act = np.clip(act, -env.force_magnitude, env.force_magnitude)
x0 = [obs[0], obs[1], 0, obs[2], obs[3], 0]
u_des = np.array([[act[0]], [act[1]], [0]])
u = rta.main(x0, u_des)
new_act = [u[0, 0], u[1, 0]]
if np.sqrt((act[0] - new_act[0])**2 +
(act[1] - new_act[1])**2) < 0.0001:
env.RTA_on = False
else:
env.RTA_on = True
return new_act
# Prepare for interaction with environment
start_time = time.time()
o, ep_ret, ep_len = env.reset(), 0, 0
total_episodes = 0
RTA_percent = 0
# Create TensorBoard file if True
if TensorBoard and proc_id() == 0:
if env_name == 'spacecraft-docking-continuous-v0' or env_name == 'spacecraft-docking-v0':
Name = f"{PATH}/runs/Spacecraft-docking-" + current_time
elif env_name == 'dubins-aircraft-v0' or env_name == 'dubins-aircraft-continuous-v0':
Name = f"{PATH}/runs/Dubins-aircraft-" + current_time
writer = SummaryWriter(Name)
# Main loop: collect experience in env and update/log each epoch
for epoch in range(epochs):
batch_ret = [] # Track episode returns
batch_len = [] # Track episode lengths
batch_RTA_percent = [] # Track precentage of time RTA is on
env.success = 0 # Track episode success rate
env.failure = 0 # Track episode failure rate
env.crash = 0 # Track episode crash rate
env.overtime = 0 # Track episode over max time/control rate
episodes = 0 # Track episodes
delta_v = [] # Track episode total delta v
for t in range(local_steps_per_epoch):
a, v, logp = ac.step(torch.as_tensor(o, dtype=torch.float32))
if RTA_type != 'off': # If RTA is on, get RTA action
RTA_a = RTA_act(o, a)
if env.RTA_on:
RTA_percent += 1
next_o, r, d, _ = env.step(RTA_a)
else: # If RTA is off, pass through desired action
next_o, r, d, _ = env.step(a)
if env_name == 'spacecraft-docking-continuous-v0' or env_name == 'spacecraft-docking-v0':
over_max_vel, _, _ = env.check_velocity(a[0], a[1])
if over_max_vel:
RTA_percent += 1
ep_ret += r
ep_len += 1
# save and log
buf.store(o, a, r, v, logp)
logger.store(VVals=v)
# Update obs (critical!)
o = next_o
timeout = ep_len == max_ep_len
terminal = d or timeout
epoch_ended = t == local_steps_per_epoch - 1
if terminal or epoch_ended:
if epoch_ended and not (terminal):
print('Warning: trajectory cut off by epoch at %d steps.' %
ep_len,
flush=True)
# if trajectory didn't reach terminal state, bootstrap value target
if timeout or epoch_ended:
_, v, _ = ac.step(torch.as_tensor(o, dtype=torch.float32))
else:
v = 0
buf.finish_path(v)
if terminal:
# only save EpRet / EpLen if trajectory finished
logger.store(EpRet=ep_ret, EpLen=ep_len)
batch_ret.append(ep_ret)
batch_len.append(ep_len)
episodes += 1
if env_name == 'spacecraft-docking-continuous-v0' or env_name == 'spacecraft-docking-v0':
delta_v.append(env.control_input / env.mass_deputy)
batch_RTA_percent.append(RTA_percent / ep_len * 100)
RTA_percent = 0
o, ep_ret, ep_len = env.reset(), 0, 0
total_episodes += episodes
# Track success, failure, crash, overtime rates
if episodes != 0:
success_rate = env.success / episodes
failure_rate = env.failure / episodes
crash_rate = env.crash / episodes
overtime_rate = env.overtime / episodes
else:
success_rate = 0
failure_rate = 0
crash_rate = 0
overtime_rate = 0
raise (
"No completed episodes logging will break [increase steps per epoch]"
)
# Save model
if (epoch % save_freq == 0) or (epoch == epochs - 1):
logger.save_state({'env': env}, None)
# Perform PPO update!
update()
# Log info about epoch
logger.log_tabular('Epoch', epoch)
logger.log_tabular('EpRet', with_min_and_max=True)
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('VVals', with_min_and_max=True)
logger.log_tabular('TotalEnvInteracts', (epoch + 1) * steps_per_epoch)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('LossV', average_only=True)
logger.log_tabular('DeltaLossPi', average_only=True)
logger.log_tabular('DeltaLossV', average_only=True)
logger.log_tabular('Entropy', average_only=True)
logger.log_tabular('KL', average_only=True)
logger.log_tabular('ClipFrac', average_only=True)
logger.log_tabular('StopIter', average_only=True)
logger.log_tabular('Time', time.time() - start_time)
logger.dump_tabular()
# Average data over all cpus
avg_batch_ret = mpi_avg(np.mean(batch_ret))
avg_batch_len = mpi_avg(np.mean(batch_len))
avg_success_rate = mpi_avg(success_rate)
avg_failure_rate = mpi_avg(failure_rate)
avg_crash_rate = mpi_avg(crash_rate)
avg_overtime_rate = mpi_avg(overtime_rate)
if env_name == 'spacecraft-docking-continuous-v0' or env_name == 'spacecraft-docking-v0':
avg_delta_v = mpi_avg(np.mean(delta_v))
avg_RTA_percent = mpi_avg(np.mean(batch_RTA_percent))
if proc_id() == 0: # Only on one cpu
# Plot to TensorBoard if True, only on one cpu
if TensorBoard:
writer.add_scalar('Return', avg_batch_ret, epoch)
writer.add_scalar('Episode-Length', avg_batch_len * env.tau,
epoch)
writer.add_scalar('Success-Rate', avg_success_rate * 100,
epoch)
writer.add_scalar('Failure-Rate', avg_failure_rate * 100,
epoch)
writer.add_scalar('Crash-Rate', avg_crash_rate * 100, epoch)
writer.add_scalar('Overtime-Rate', avg_overtime_rate * 100,
epoch)
if env_name == 'spacecraft-docking-continuous-v0' or env_name == 'spacecraft-docking-v0':
writer.add_scalar('Delta-V', avg_delta_v, epoch)
writer.add_scalar('RTA-on-percent', avg_RTA_percent, epoch)
# Save neural network if true, can change to desired location
if save_nn and epoch % save_every == 0 and epoch != 0:
if not os.path.isdir(f"{PATH}/models"):
os.mkdir(f"{PATH}/models")
if not os.path.isdir(f"{PATH}/models/PPO"):
os.mkdir(f"{PATH}/models/PPO")
if env_name == 'spacecraft-docking-continuous-v0' or env_name == 'spacecraft-docking-v0':
Name2 = f"{PATH}/models/PPO/Spacecraft-docking-" + current_time + f"-epoch{epoch}.dat"
elif env_name == 'dubins-aircraft-v0' or env_name == 'dubins-aircraft-continuous-v0':
Name2 = f"{PATH}/models/PPO/Dubins-aircraft-" + current_time + f"-epoch{epoch}.dat"
torch.save(ac.state_dict(), Name2)
# Average episodes per hour, episode per epoch
ep_hr = mpi_avg(total_episodes) * args.cpu / (time.time() -
start_time) * 3600
ep_Ep = mpi_avg(total_episodes) * args.cpu / (epoch + 1)
# Plot on one cpu
if proc_id() == 0:
# Save neural network
if save_nn:
if not os.path.isdir(f"{PATH}/models"):
os.mkdir(f"{PATH}/models")
if not os.path.isdir(f"{PATH}/models/PPO"):
os.mkdir(f"{PATH}/models/PPO")
if env_name == 'spacecraft-docking-continuous-v0' or env_name == 'spacecraft-docking-v0':
Name2 = f"{PATH}/models/PPO/Spacecraft-docking-" + current_time + "-final.dat"
elif env_name == 'dubins-aircraft-v0' or env_name == 'dubins-aircraft-continuous-v0':
Name2 = f"{PATH}/models/PPO/Dubins-aircraft-" + current_time + "-final.dat"
torch.save(ac.state_dict(), Name2)
# Print statistics on episodes
print(
f"Episodes per hour: {ep_hr:.0f}, Episodes per epoch: {ep_Ep:.0f}, Epochs per hour: {(epoch+1)/(time.time()-start_time)*3600:.0f}"
)
def ddpg(env_config, ac_type, ac_kwargs, rb_type, rb_kwargs, gamma, lr, polyak,
batch_size, epochs, start_steps, steps_per_epoch, inc_ep, max_ep_len,
test_max_ep_len, number_of_tests_per_epoch, act_noise, logger_kwargs,
seed):
logger = EpochLogger(**logger_kwargs)
configs = locals().copy()
configs.pop("logger")
logger.save_config(configs)
tf.set_random_seed(seed)
np.random.seed(seed)
env, test_env = make_env(env_config), make_env(env_config)
obs_dim = env.observation_space.shape[0]
act_dim = env.action_space.shape[0]
# Action limit for clamping: critically, assumes all dimensions share the same bound!
act_high = env.action_space.high
# Inputs to computation graph
x_ph, a_ph, x2_ph, r_ph, d_ph = core.placeholders(obs_dim, act_dim,
obs_dim, None, None)
actor_critic = core.get_ddpg_actor_critic(ac_type)
# Main outputs from computation graph
with tf.variable_scope('main'):
pi, q, q_pi = actor_critic(x_ph, a_ph, **ac_kwargs)
# Target networks
with tf.variable_scope('target'):
pi_targ, _, q_pi_targ = actor_critic(x2_ph, a_ph, **ac_kwargs)
# Experience buffer
RB = get_replay_buffer(rb_type)
replay_buffer = RB(obs_dim, act_dim, **rb_kwargs)
# Count variables
var_counts = tuple(
core.count_vars(scope) for scope in ['main/pi', 'main/q', 'main'])
print('\nNumber of parameters: \t pi: %d, \t q: %d, \t total: %d\n' %
var_counts)
# Bellman backup for Q function
backup = tf.stop_gradient(r_ph + gamma * (1 - d_ph) * q_pi_targ)
# DDPG losses
pi_loss = -tf.reduce_mean(q_pi)
q_loss = tf.reduce_mean((q - backup)**2)
# Separate train ops for pi, q
pi_optimizer = tf.train.AdamOptimizer(learning_rate=lr)
q_optimizer = tf.train.AdamOptimizer(learning_rate=lr)
train_pi_op = pi_optimizer.minimize(pi_loss, var_list=get_vars('main/pi'))
train_q_op = q_optimizer.minimize(q_loss, var_list=get_vars('main/q'))
# Polyak averaging for target variables
target_update = tf.group([
tf.assign(v_targ, polyak * v_targ + (1 - polyak) * v_main)
for v_main, v_targ in zip(get_vars('main'), get_vars('target'))
])
# Initializing targets to match main variables
target_init = tf.group([
tf.assign(v_targ, v_main)
for v_main, v_targ in zip(get_vars('main'), get_vars('target'))
])
sess = tf.Session()
sess.run(tf.global_variables_initializer())
sess.run(target_init)
def get_action(o, noise_scale):
pi_a = sess.run(pi, feed_dict={x_ph: o.reshape(1, -1)})[0]
pi_a += noise_scale * np.random.randn(act_dim)
pi_a = np.clip(pi_a, 0, 1)
real_a = pi_a * act_high
return pi_a, real_a
def test_agent(n=10):
test_actions = []
for j in range(n):
test_actions_ep = []
o, r, d, ep_ret, ep_len = test_env.reset(), 0, False, 0, 0
while not (d or (ep_len == test_max_ep_len)):
# Take deterministic actions at test time (noise_scale=0)
_, real_a = get_action(o, 0)
test_actions_ep.append(real_a)
o, r, d, _ = test_env.step(real_a)
ep_ret += r
ep_len += 1
logger.store(TestEpRet=ep_ret, TestEpLen=ep_len)
test_actions.append(test_actions_ep)
return test_actions
start_time = time.time()
o, r, d, ep_ret, ep_len = env.reset(), 0, False, 0, 0
total_steps = steps_per_epoch * epochs
actions = []
epoch_actions = []
rewards = []
rets = []
test_rets = []
max_ret = None
# Main loop: collect experience in env and update/log each epoch
for t in range(total_steps):
"""
Until start_steps have elapsed, randomly sample actions
from a uniform distribution for better exploration. Afterwards,
use the learned policy (with some noise, via act_noise).
"""
if t > start_steps:
pi_a, real_a = get_action(o, act_noise)
else:
pi_a, real_a = env.action_space.sample()
# Step the env
o2, r, d, _ = env.step(real_a)
ep_ret += r
ep_len += 1
epoch_actions.append(pi_a)
# Ignore the "done" signal if it comes from hitting the time
# horizon (that is, when it's an artificial terminal signal
# that isn't based on the agent's state)
d = False if ep_len == max_ep_len else d
# Store experience to replay buffer
replay_buffer.store(o, pi_a, r, o2, d)
# Super critical, easy to overlook step: make sure to update
# most recent observation!
o = o2
if d or (ep_len == max_ep_len):
"""
Perform all DDPG updates at the end of the trajectory,
in accordance with tuning done by TD3 paper authors.
"""
for _ in range(ep_len):
batch = replay_buffer.sample_batch(batch_size)
feed_dict = {
x_ph: batch['obs1'],
x2_ph: batch['obs2'],
a_ph: batch['acts'],
r_ph: batch['rews'],
d_ph: batch['done']
}
# Q-learning update
outs = sess.run([q_loss, q, train_q_op], feed_dict)
logger.store(LossQ=outs[0], QVals=outs[1])
# Policy update
outs = sess.run([pi_loss, train_pi_op, target_update],
feed_dict)
logger.store(LossPi=outs[0])
logger.store(EpRet=ep_ret, EpLen=ep_len)
actions.append(np.mean(epoch_actions))
epoch_actions = []
rewards.append(ep_ret)
o, r, d, ep_ret, ep_len = env.reset(), 0, False, 0, 0
# End of epoch wrap-up
if (t + 1) % steps_per_epoch == 0:
epoch = (t + 1) // steps_per_epoch
# Test the performance of the deterministic version of the agent.
test_actions = test_agent(number_of_tests_per_epoch)
# Log info about epoch
logger.log_tabular('Epoch', epoch)
ret = logger.log_tabular('EpRet', average_only=True)
test_ret = logger.log_tabular('TestEpRet', average_only=True)[0]
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('TestEpLen', average_only=True)
logger.log_tabular('QVals', average_only=True)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('LossQ', average_only=True)
logger.log_tabular('Time', time.time() - start_time)
logger.dump_tabular()
rets.append(ret)
test_rets.append(test_ret)
if max_ret is None or test_ret > max_ret:
max_ret = test_ret
best_test_actions = test_actions
max_ep_len += inc_ep
util.plot_actions(test_actions, act_high,
logger.output_dir + '/actions%s.png' % epoch)
logger.save_state(
{
"actions": actions,
"rewards": rewards,
"best_test_actions": best_test_actions,
"rets": rets,
"test_rets": test_rets,
"max_ret": max_ret
}, None)
util.plot_actions(best_test_actions, act_high,
logger.output_dir + '/best_test_actions.png')
logger.log("max ret: %f" % max_ret)
def sac(args, steps_per_epoch=1500, replay_size=int(1e6), gamma=0.99,
polyak=0.995, lr=1e-3, alpha=3e-4, batch_size=128, start_steps=1000,
update_after=1000, update_every=1, num_test_episodes=10, max_ep_len=150,
logger_kwargs=dict(), save_freq=1):
logger_kwargs = setup_logger_kwargs(args.exp_name, args.seed)
torch.set_num_threads(torch.get_num_threads())
actor_critic = core.MLPActorCritic
ac_kwargs = dict(hidden_sizes=[args.hid] * args.l)
gamma = args.gamma
seed = args.seed
epochs = args.epochs
logger_tensor = Logger(logdir=args.logdir, run_name="{}-{}".format(args.model_name, time.ctime()))
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
torch.manual_seed(seed)
np.random.seed(seed)
env = ML1.get_train_tasks('reach-v1') # Create an environment with task `pick_place`
tasks = env.sample_tasks(1) # Sample a task (in this case, a goal variation)
env.set_task(tasks[0]) # Set task
test_env = ML1.get_train_tasks('reach-v1') # Create an environment with task `pick_place`
tasks = env.sample_tasks(1) # Sample a task (in this case, a goal variation)
test_env.set_task(tasks[0]) # Set task
obs_dim = env.observation_space.shape
act_dim = env.action_space.shape[0]
# Action limit for clamping: critically, assumes all dimensions share the same bound!
act_limit = env.action_space.high[0]
# Create actor-critic module and target networks
ac = actor_critic(env.observation_space, env.action_space, **ac_kwargs)
ac_targ = deepcopy(ac)
# Freeze target networks with respect to optimizers (only update via polyak averaging)
for p in ac_targ.parameters():
p.requires_grad = False
# List of parameters for both Q-networks (save this for convenience)
q_params = itertools.chain(ac.q1.parameters(), ac.q2.parameters())
# Experience buffer
replay_buffer = ReplayBuffer(obs_dim=obs_dim, act_dim=act_dim, size=replay_size)
# Count variables (protip: try to get a feel for how different size networks behave!)
var_counts = tuple(core.count_vars(module) for module in [ac.pi, ac.q1, ac.q2])
logger.log('\nNumber of parameters: \t pi: %d, \t q1: %d, \t q2: %d\n' % var_counts)
# Set up function for computing SAC Q-losses
def compute_loss_q(data):
o, a, r, o2, d = data['obs'], data['act'], data['rew'], data['obs2'], data['done']
q1 = ac.q1(o, a)
q2 = ac.q2(o, a)
# Bellman backup for Q functions
with torch.no_grad():
# Target actions come from *current* policy
a2, logp_a2 = ac.pi(o2)
# Target Q-values
q1_pi_targ = ac_targ.q1(o2, a2)
q2_pi_targ = ac_targ.q2(o2, a2)
q_pi_targ = torch.min(q1_pi_targ, q2_pi_targ)
backup = r + gamma * (1 - d) * (q_pi_targ - alpha * logp_a2)
# MSE loss against Bellman backup
loss_q1 = ((q1 - backup) ** 2).mean()
loss_q2 = ((q2 - backup) ** 2).mean()
loss_q = loss_q1 + loss_q2
# Useful info for logging
q_info = dict(Q1Vals=q1.detach().numpy(),
Q2Vals=q2.detach().numpy())
return loss_q, q_info
# Set up function for computing SAC pi loss
def compute_loss_pi(data):
o = data['obs']
pi, logp_pi = ac.pi(o)
q1_pi = ac.q1(o, pi)
q2_pi = ac.q2(o, pi)
q_pi = torch.min(q1_pi, q2_pi)
# Entropy-regularized policy loss
loss_pi = (alpha * logp_pi - q_pi).mean()
# Useful info for logging
pi_info = dict(LogPi=logp_pi.detach().numpy())
return loss_pi, pi_info
# Set up optimizers for policy and q-function
pi_optimizer = Adam(ac.pi.parameters(), lr=3e-4)
q_optimizer = Adam(q_params, lr=3e-4)
# Set up model saving
logger.setup_pytorch_saver(ac)
def update(data, logger_tensor, t):
# First run one gradient descent step for Q1 and Q2
q_optimizer.zero_grad()
loss_q, q_info = compute_loss_q(data)
loss_q.backward()
q_optimizer.step()
# Record things
logger.store(LossQ=loss_q.item(), **q_info)
logger_tensor.log_value(t, loss_q.item(), "loss q")
# Freeze Q-networks so you don't waste computational effort
# computing gradients for them during the policy learning step.
for p in q_params:
p.requires_grad = False
# Next run one gradient descent step for pi.
pi_optimizer.zero_grad()
loss_pi, pi_info = compute_loss_pi(data)
loss_pi.backward()
pi_optimizer.step()
# Unfreeze Q-networks so you can optimize it at next DDPG step.
for p in q_params:
p.requires_grad = True
# Record things
logger.store(LossPi=loss_pi.item(), **pi_info)
logger_tensor.log_value(t, loss_pi.item(), "loss pi")
# Finally, update target networks by polyak averaging.
with torch.no_grad():
for p, p_targ in zip(ac.parameters(), ac_targ.parameters()):
# NB: We use an in-place operations "mul_", "add_" to update target
# params, as opposed to "mul" and "add", which would make new tensors.
p_targ.data.mul_(polyak)
p_targ.data.add_((1 - polyak) * p.data)
def get_action(o, deterministic=False):
return ac.act(torch.as_tensor(o, dtype=torch.float32),
deterministic)
def test_agent():
for j in range(num_test_episodes):
o, d, ep_ret, ep_len = test_env.reset(), False, 0, 0
while not (d or (ep_len == max_ep_len)):
# Take deterministic actions at test time
o, r, d, _ = test_env.step(get_action(o, True))
ep_ret += r
ep_len += 1
logger.store(TestEpRet=ep_ret, TestEpLen=ep_len)
logger_tensor.log_value(t, ep_ret, "test ep reward")
logger_tensor.log_value(t, ep_len, "test ep length")
# Prepare for interaction with environment
total_steps = steps_per_epoch * epochs
start_time = time.time()
o, ep_ret, ep_len = env.reset(), 0, 0
# Main loop: collect experience in env and update/log each epoch
for t in range(total_steps):
# Until start_steps have elapsed, randomly sample actions
# from a uniform distribution for better exploration. Afterwards,
# use the learned policy.
if t > start_steps:
a = get_action(o)
else:
a = env.action_space.sample()
# Step the env
o2, r, d, _ = env.step(a)
ep_ret += r
ep_len += 1
# Ignore the "done" signal if it comes from hitting the time
# horizon (that is, when it's an artificial terminal signal
# that isn't based on the agent's state)
d = False if ep_len == max_ep_len else d
# Store experience to replay buffer
replay_buffer.store(o, a, r, o2, d)
# Super critical, easy to overlook step: make sure to update
# most recent observation!
o = o2
# End of trajectory handling
if d or (ep_len == max_ep_len):
logger_tensor.log_value(t, ep_ret, "reward")
logging.info("> total_steps={} | reward={}".format(t, ep_ret))
logger.store(EpRet=ep_ret, EpLen=ep_len)
o, ep_ret, ep_len = env.reset(), 0, 0
# Update handling
if t >= update_after and t % update_every == 0:
for j in range(update_every):
batch = replay_buffer.sample_batch(batch_size)
update(data=batch, logger_tensor = logger_tensor, t = t)
# End of epoch handling
if (t + 1) % steps_per_epoch == 0:
epoch = (t + 1) // steps_per_epoch
# Save model
if (epoch % save_freq == 0) or (epoch == epochs):
logger.save_state({'env': env}, None)
# Test the performance of the deterministic version of the agent.
test_agent()
# Log info about epoch
logger.log_tabular('Epoch', epoch)
logger.log_tabular('EpRet', with_min_and_max=True)
logger.log_tabular('TestEpRet', with_min_and_max=True)
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('TestEpLen', average_only=True)
logger.log_tabular('TotalEnvInteracts', t)
logger.log_tabular('Q1Vals', with_min_and_max=True)
logger.log_tabular('Q2Vals', with_min_and_max=True)
logger.log_tabular('LogPi', with_min_and_max=True)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('LossQ', average_only=True)
logger.log_tabular('Time', time.time() - start_time)
logger_tensor.log_value(t, epoch, "epoch")
logger.dump_tabular(logger_tensor=logger_tensor,epoch = epoch)
ac.save(args.save_model_dir, args.model_name)
def ppo(env_fn,
actor_critic=a2c,
ac_kwargs=dict(),
seed=0,
steps_per_epoch=4000,
epochs=50,
gamma=.99,
clip_ratio=.2,
pi_lr=3e-4,
vf_lr=1e-3,
train_pi_iters=80,
train_v_iters=80,
lam=.97,
max_ep_len=1000,
target_kl=.01,
logger_kwargs=dict(),
save_freq=10):
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
seed += 10000 * proc_id()
tf.set_random_seed(seed)
np.random.seed(seed)
env = env_fn()
obs_dim = env.observation_space.shape[0]
act_dim = env.action_space.shape[0]
# Share action space structure with the actor_critic
ac_kwargs['action_space'] = env.action_space
x_ph, a_ph = tf.placeholder( name="x_ph", shape=[None, obs_dim], dtype=tf.float32), \
tf.placeholder( name="a_ph", shape=[None, act_dim], dtype=tf.float32)
adv_ph, ret_ph, logp_old_ph = tf.placeholder( name="adv_ph", shape=[None], dtype=tf.float32), \
tf.placeholder( name="ret_ph", shape=[None], dtype=tf.float32), \
tf.placeholder( name="logp_old_ph", shape=[None], dtype=tf.float32)
# Main outputs from computation graph
# print( actor_critic( x_ph, a_ph, **ac_kwargs))
pi, logp, logp_pi, v = actor_critic(x_ph, a_ph, **ac_kwargs)
all_phs = [x_ph, a_ph, adv_ph, ret_ph, logp_old_ph]
get_action_ops = [pi, v, logp_pi]
local_steps_per_epoch = int(steps_per_epoch / num_procs())
buf = PPOBuffer(obs_dim, act_dim, local_steps_per_epoch, gamma, lam)
# helpers for var count
def get_vars(scope=''):
return [x for x in tf.trainable_variables() if scope in x.name]
def count_vars(scope=''):
v = get_vars(scope)
return sum([np.prod(var.shape.as_list()) for var in v])
var_counts = tuple(count_vars(scope) for scope in ['pi', 'v'])
logger.log('\nNumber of parameters: \t pi: %d, \t v: %d\n' % var_counts)
# PPO Objectives
ratio = tf.exp(logp - logp_old_ph)
min_adv = tf.where(adv_ph > 0, (1 + clip_ratio) * adv_ph,
(1 - clip_ratio) * adv_ph)
pi_loss = -tf.reduce_mean(tf.minimum(ratio * adv_ph, min_adv))
v_loss = tf.reduce_mean((ret_ph - v)**2)
# Stats to watch
approx_kl = tf.reduce_mean(
logp_old_ph -
logp) # a sample estimate for KL-divergence, easy to compute
approx_ent = tf.reduce_mean(-logp)
clipped = tf.logical_or(ratio > (1 + clip_ratio), ratio < (1 - clip_ratio))
clipfrac = tf.reduce_mean(tf.cast(clipped, tf.float32))
train_pi = MpiAdamOptimizer(learning_rate=pi_lr).minimize(pi_loss)
train_v = MpiAdamOptimizer(learning_rate=vf_lr).minimize(v_loss)
sess = tf.Session()
sess.run(tf.global_variables_initializer())
# Sync params across processes
sess.run(sync_all_params())
# Setup model saving
logger.setup_tf_saver(sess, inputs={'x': x_ph}, outputs={'pi': pi, 'v': v})
def update():
inputs = {k: v for k, v in zip(all_phs, buf.get())}
pi_l_old, v_l_old, ent = sess.run([pi_loss, v_loss, approx_ent],
feed_dict=inputs)
for i in range(train_pi_iters):
_, kl = sess.run([train_pi, approx_kl], feed_dict=inputs)
def mpi_avg(x):
"""Average a scalar or vector over MPI processes."""
return mpi_sum(x) / num_procs()
kl = mpi_avg(kl)
if kl > 1.5 * target_kl:
logger.log(
'Early stopping at step %d due to reaching max kl.' % i)
break
logger.store(StopIter=i)
for _ in range(train_v_iters):
sess.run(train_v, feed_dict=inputs)
# Log changes from update
pi_l_new, v_l_new, kl, cf = sess.run(
[pi_loss, v_loss, approx_kl, clipfrac], feed_dict=inputs)
logger.store(LossPi=pi_l_old,
LossV=v_l_old,
KL=kl,
Entropy=ent,
ClipFrac=cf,
DeltaLossPi=(pi_l_new - pi_l_old),
DeltaLossV=(v_l_new - v_l_old))
start_time = time.time()
o, r, d, ep_ret, ep_len = env.reset(), 0, False, 0, 0
for epoch in range(epochs):
for t in range(local_steps_per_epoch):
a, v_t, logp_t = sess.run(get_action_ops,
feed_dict={x_ph: o.reshape(1, -1)})
# save and log
buf.store(o, a, r, v_t, logp_t)
logger.store(VVals=v_t)
o, r, d, _ = env.step(a[0])
ep_ret += r
ep_len += 1
terminal = d or (ep_len == max_ep_len)
if terminal or (t == local_steps_per_epoch - 1):
if not (terminal):
print('Warning: trajectory cut off by epoch at %d steps.' %
ep_len)
# if trajectory didn't reach terminal state, bootstrap value target
last_val = r if d else sess.run(
v, feed_dict={x_ph: o.reshape(1, -1)})
buf.finish_path(last_val)
if terminal:
# only save EpRet / EpLen if trajectory finished
logger.store(EpRet=ep_ret, EpLen=ep_len)
o, r, d, ep_ret, ep_len = env.reset(), 0, False, 0, 0
# Save model
if (epoch % save_freq == 0) or (epoch == epochs - 1):
logger.save_state({'env': env}, None)
# Perform PPO update!
update()
# Log info about epoch
logger.log_tabular('Epoch', epoch)
logger.log_tabular('EpRet', with_min_and_max=True)
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('VVals', with_min_and_max=True)
logger.log_tabular('TotalEnvInteracts', (epoch + 1) * steps_per_epoch)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('LossV', average_only=True)
logger.log_tabular('DeltaLossPi', average_only=True)
logger.log_tabular('DeltaLossV', average_only=True)
logger.log_tabular('Entropy', average_only=True)
logger.log_tabular('KL', average_only=True)
logger.log_tabular('ClipFrac', average_only=True)
logger.log_tabular('StopIter', average_only=True)
logger.log_tabular('Time', time.time() - start_time)
logger.dump_tabular()
def ppo(env_fn,
actor_critic=core.MLPActorCritic,
ac_kwargs=dict(),
seed=0,
steps_per_epoch=4000,
epochs=50,
gamma=0.99,
clip_ratio=0.2,
pi_lr=3e-4,
vf_lr=1e-3,
train_pi_iters=80,
train_v_iters=80,
lam=0.97,
max_ep_len=1000,
target_kl=0.01,
logger_kwargs=dict(),
save_freq=10):
"""
Proximal Policy Optimization (by clipping),
with early stopping based on approximate KL
Args:
env_fn : A function which creates a copy of the environment.
The environment must satisfy the OpenAI Gym API.
actor_critic: The constructor method for a PyTorch Module with a
``step`` method, an ``act`` method, a ``pi`` module, and a ``v``
module. The ``step`` method should accept a batch of observations
and return:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``a`` (batch, act_dim) | Numpy array of actions for each
| observation.
``v`` (batch,) | Numpy array of value estimates
| for the provided observations.
``logp_a`` (batch,) | Numpy array of log probs for the
| actions in ``a``.
=========== ================ ======================================
The ``act`` method behaves the same as ``step`` but only returns ``a``.
The ``pi`` module's forward call should accept a batch of
observations and optionally a batch of actions, and return:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``pi`` N/A | Torch Distribution object, containing
| a batch of distributions describing
| the policy for the provided observations.
``logp_a`` (batch,) | Optional (only returned if batch of
| actions is given). Tensor containing
| the log probability, according to
| the policy, of the provided actions.
| If actions not given, will contain
| ``None``.
=========== ================ ======================================
The ``v`` module's forward call should accept a batch of observations
and return:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``v`` (batch,) | Tensor containing the value estimates
| for the provided observations. (Critical:
| make sure to flatten this!)
=========== ================ ======================================
ac_kwargs (dict): Any kwargs appropriate for the ActorCritic object
you provided to PPO.
seed (int): Seed for random number generators.
steps_per_epoch (int): Number of steps of interaction (state-action pairs)
for the agent and the environment in each epoch.
epochs (int): Number of epochs of interaction (equivalent to
number of policy updates) to perform.
gamma (float): Discount factor. (Always between 0 and 1.)
clip_ratio (float): Hyperparameter for clipping in the policy objective.
Roughly: how far can the new policy go from the old policy while
still profiting (improving the objective function)? The new policy
can still go farther than the clip_ratio says, but it doesn't help
on the objective anymore. (Usually small, 0.1 to 0.3.) Typically
denoted by :math:`\epsilon`.
pi_lr (float): Learning rate for policy optimizer.
vf_lr (float): Learning rate for value function optimizer.
train_pi_iters (int): Maximum number of gradient descent steps to take
on policy loss per epoch. (Early stopping may cause optimizer
to take fewer than this.)
train_v_iters (int): Number of gradient descent steps to take on
value function per epoch.
lam (float): Lambda for GAE-Lambda. (Always between 0 and 1,
close to 1.)
max_ep_len (int): Maximum length of trajectory / episode / rollout.
target_kl (float): Roughly what KL divergence we think is appropriate
between new and old policies after an update. This will get used
for early stopping. (Usually small, 0.01 or 0.05.)
logger_kwargs (dict): Keyword args for EpochLogger.
save_freq (int): How often (in terms of gap between epochs) to save
the current policy and value function.
"""
# GAedit
# Special function to avoid certain slowdowns from PyTorch + MPI combo.
# setup_pytorch_for_mpi()
# Set up logger and save configuration
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
# GAedit
# Seed
seed = 333
torch.manual_seed(seed)
np.random.seed(seed)
# Instantiate environment
env = env_fn()
#GAedit
# obs_dim = env.observation_space.shape
# act_dim = env.action_space.shape
# get the default brain
brain_name = env.brain_names[0]
brain = env.brains[brain_name]
# reset the environment
env_info = env.reset(train_mode=True)[brain_name]
# number of agents
num_agents = len(env_info.agents)
# size of each action
act_dim = brain.vector_action_space_size
# examine the state space
obs_dim = env_info.vector_observations.shape[1]
#GAedit
# Create actor-critic module
# ac = actor_critic(env.observation_space, env.action_space, **ac_kwargs)
ac = actor_critic(obs_dim, act_dim, **ac_kwargs)
# GAedit - don't think we need to sync
# Sync params across processes
# sync_params(ac)
# Count variables
var_counts = tuple(core.count_vars(module) for module in [ac.pi, ac.v])
logger.log('\nNumber of parameters: \t pi: %d, \t v: %d\n' % var_counts)
# Set up experience buffer
# GAedit
# local_steps_per_epoch = int(steps_per_epoch / num_procs())
local_steps_per_epoch = int(steps_per_epoch / num_agents)
#GAedit
buf = PPOBuffer(obs_dim, act_dim, local_steps_per_epoch * num_agents,
gamma, lam)
# buf = PPOBuffer(obs_dim, act_dim, local_steps_per_epoch, gamma, lam)
# Set up function for computing PPO policy loss
def compute_loss_pi(data):
obs, act, adv, logp_old = data['obs'], data['act'], data['adv'], data[
'logp']
# Policy loss
pi, logp = ac.pi(obs, act)
ratio = torch.exp(logp - logp_old)
clip_adv = torch.clamp(ratio, 1 - clip_ratio, 1 + clip_ratio) * adv
loss_pi = -(torch.min(ratio * adv, clip_adv)).mean()
# Useful extra info
approx_kl = (logp_old - logp).mean().item()
ent = pi.entropy().mean().item()
clipped = ratio.gt(1 + clip_ratio) | ratio.lt(1 - clip_ratio)
clipfrac = torch.as_tensor(clipped, dtype=torch.float32).mean().item()
pi_info = dict(kl=approx_kl, ent=ent, cf=clipfrac)
return loss_pi, pi_info
# Set up function for computing value loss
def compute_loss_v(data):
obs, ret = data['obs'], data['ret']
return ((ac.v(obs) - ret)**2).mean()
# Set up optimizers for policy and value function
pi_optimizer = Adam(ac.pi.parameters(), lr=pi_lr)
vf_optimizer = Adam(ac.v.parameters(), lr=vf_lr)
# Set up model saving
logger.setup_pytorch_saver(ac)
def update():
data = buf.get()
pi_l_old, pi_info_old = compute_loss_pi(data)
pi_l_old = pi_l_old.item()
v_l_old = compute_loss_v(data).item()
# Train policy with multiple steps of gradient descent
for i in range(train_pi_iters):
pi_optimizer.zero_grad()
loss_pi, pi_info = compute_loss_pi(data)
#GAedit
# kl = mpi_avg(pi_info['kl'])
kl = pi_info['kl']
if kl > 1.5 * target_kl:
logger.log(
'Early stopping at step %d due to reaching max kl.' % i)
break
loss_pi.backward()
#GAedit
# mpi_avg_grads(ac.pi) # average grads across MPI processes
# ac.pi.mean()
pi_optimizer.step()
logger.store(StopIter=i)
# Value function learning
for i in range(train_v_iters):
vf_optimizer.zero_grad()
loss_v = compute_loss_v(data)
loss_v.backward()
#GAedit
# mpi_avg_grads(ac.v) # average grads across MPI processes
vf_optimizer.step()
# Log changes from update
kl, ent, cf = pi_info['kl'], pi_info_old['ent'], pi_info['cf']
logger.store(LossPi=pi_l_old,
LossV=v_l_old,
KL=kl,
Entropy=ent,
ClipFrac=cf,
DeltaLossPi=(loss_pi.item() - pi_l_old),
DeltaLossV=(loss_v.item() - v_l_old))
# Prepare for interaction with environment
start_time = time.time()
#GAedit
# o, ep_ret, ep_len = env.reset(), 0, 0
ep_ret, ep_len = 0, 0
env_info = env.reset(train_mode=True)[brain_name]
o = env_info.vector_observations
# Main loop: collect experience in env and update/log each epoch
for epoch in range(epochs):
for t in range(local_steps_per_epoch):
a, v, logp = ac.step(torch.as_tensor(o, dtype=torch.float32))
# GAedit
# next_o, r, d, _ = env.step(a)
env_info = env.step(a)[brain_name]
next_o, r, d = env_info.vector_observations, env_info.rewards, env_info.local_done
#GAedit
# ep_ret += r
ep_ret += np.mean(r)
ep_len += 1
# save and log
#GAedit
# buf.store(o, a, r, v, logp)
for i in range(20):
buf.store(o[i], a[i], r[i], v[i], logp[i])
logger.store(VVals=v)
# Update obs (critical!)
o = next_o
timeout = ep_len == max_ep_len
# GAedit
# terminal = d or timeout
terminal = any(d) or timeout
epoch_ended = t == local_steps_per_epoch - 1
if terminal or epoch_ended:
if epoch_ended and not (terminal):
print('Warning: trajectory cut off by epoch at %d steps.' %
ep_len,
flush=True)
# if trajectory didn't reach terminal state, bootstrap value target
if timeout or epoch_ended:
_, v, _ = ac.step(torch.as_tensor(o, dtype=torch.float32))
else:
v = 0
buf.finish_path(v)
if terminal:
# only save EpRet / EpLen if trajectory finished
logger.store(EpRet=ep_ret, EpLen=ep_len)
# GAedit
# o, ep_ret, ep_len = env.reset(), 0, 0
ep_ret, ep_len = 0, 0
env_info = env.reset(train_mode=True)[brain_name]
o = env_info.vector_observations
# Save model
if (epoch % save_freq == 0) or (epoch == epochs - 1):
logger.save_state({'env': env}, None)
# Perform PPO update!
update()
# Log info about epoch
logger.log_tabular('Epoch', epoch)
logger.log_tabular('EpRet', with_min_and_max=True)
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('VVals', with_min_and_max=True)
logger.log_tabular('TotalEnvInteracts', (epoch + 1) * steps_per_epoch)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('LossV', average_only=True)
logger.log_tabular('DeltaLossPi', average_only=True)
logger.log_tabular('DeltaLossV', average_only=True)
logger.log_tabular('Entropy', average_only=True)
logger.log_tabular('KL', average_only=True)
logger.log_tabular('ClipFrac', average_only=True)
logger.log_tabular('StopIter', average_only=True)
logger.log_tabular('Time', time.time() - start_time)
logger.dump_tabular()
def ppo(env_fn,
actor_critic=core.mlp_actor_critic,
ac_kwargs=dict(),
seed=0,
trials_per_epoch=2500,
steps_per_trial=100,
epochs=50,
gamma=0.99,
clip_ratio=0.2,
pi_lr=3e-4,
vf_lr=1e-3,
train_pi_iters=1000,
train_v_iters=80,
lam=0.97,
max_ep_len=1000,
target_kl=0.01,
logger_kwargs=dict(),
save_freq=10):
"""
Args:
env_fn : A function which creates a copy of the environment.
The environment must satisfy the OpenAI Gym API.
actor_critic: A function which takes in placeholder symbols
for state, ``x_ph``, and action, ``a_ph``, and returns the main
outputs from the agent's Tensorflow computation graph:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``pi`` (batch, act_dim) | Samples actions from policy given
| states.
``logp`` (batch,) | Gives log probability, according to
| the policy, of taking actions ``a_ph``
| in states ``x_ph``.
``logp_pi`` (batch,) | Gives log probability, according to
| the policy, of the action sampled by
| ``pi``.
``v`` (batch,) | Gives the value estimate for states
| in ``x_ph``. (Critical: make sure
| to flatten this!)
=========== ================ ======================================
ac_kwargs (dict): Any kwargs appropriate for the actor_critic
function you provided to PPO.
seed (int): Seed for random number generators.
steps_per_epoch (int): Number of steps of interaction (state-action pairs)
for the agent and the environment in each epoch.
epochs (int): Number of epochs of interaction (equivalent to
number of policy updates) to perform.
gamma (float): Discount factor. (Always between 0 and 1.)
clip_ratio (float): Hyperparameter for clipping in the policy objective.
Roughly: how far can the new policy go from the old policy while
still profiting (improving the objective function)? The new policy
can still go farther than the clip_ratio says, but it doesn't help
on the objective anymore. (Usually small, 0.1 to 0.3.)
pi_lr (float): Learning rate for policy optimizer.
vf_lr (float): Learning rate for value function optimizer.
train_pi_iters (int): Maximum number of gradient descent steps to take
on policy loss per epoch. (Early stopping may cause optimizer
to take fewer than this.)
train_v_iters (int): Number of gradient descent steps to take on
value function per epoch.
lam (float): Lambda for GAE-Lambda. (Always between 0 and 1,
close to 1.)
max_ep_len (int): Maximum length of trajectory / episode / rollout.
target_kl (float): Roughly what KL divergence we think is appropriate
between new and old policies after an update. This will get used
for early stopping. (Usually small, 0.01 or 0.05.)
logger_kwargs (dict): Keyword args for EpochLogger.
save_freq (int): How often (in terms of gap between epochs) to save
the current policy and value function.
"""
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
seed += 10000 * proc_id()
tf.set_random_seed(seed)
np.random.seed(seed)
env = env_fn()
obs_dim = env.observation_space.shape
act_dim = env.action_space.shape
# Share information about action space with policy architecture
ac_kwargs['action_space'] = env.action_space
# Inputs to computation graph
# x_ph, a_ph = core.placeholders_from_spaces(env.observation_space, env.action_space)
x_ph = tf.placeholder(dtype=tf.float32, shape=(None, None, 1), name='x_ph')
a_ph = tf.placeholder(dtype=tf.int32, shape=(None, None), name='a_ph')
# adv_ph, ret_ph, logp_old_ph, rew_ph = core.placeholders(None, None, None, 1)
adv_ph = tf.placeholder(dtype=tf.float32,
shape=(None, None),
name='adv_ph')
ret_ph = tf.placeholder(dtype=tf.float32,
shape=(None, None),
name='ret_ph')
logp_old_ph = tf.placeholder(dtype=tf.float32,
shape=(None, None),
name='logp_old_ph')
rew_ph = tf.placeholder(dtype=tf.float32,
shape=(None, None, 1),
name='rew_ph')
pi_state_ph = tf.placeholder(dtype=tf.float32,
shape=(None, NUM_GRU_UNITS),
name='pi_state_ph')
v_state_ph = tf.placeholder(dtype=tf.float32,
shape=(None, NUM_GRU_UNITS),
name='v_state_ph')
# Initialize rnn states for pi and v
# Main outputs from computation graph
pi, logp, logp_pi, v, new_pi_state, new_v_state = actor_critic(
x_ph,
a_ph,
rew_ph,
pi_state_ph,
v_state_ph,
NUM_GRU_UNITS,
action_space=env.action_space)
# Need all placeholders in *this* order later (to zip with data from buffer)
all_phs = [x_ph, a_ph, adv_ph, ret_ph, logp_old_ph, rew_ph]
# Every step, get: action, value, and logprob and reward
get_action_ops = [pi, v, logp_pi, new_pi_state, new_v_state]
# Experience buffer
steps_per_epoch = trials_per_epoch * steps_per_trial
local_steps_per_epoch = int(steps_per_epoch / num_procs())
buf = PPOBuffer(obs_dim, act_dim, local_steps_per_epoch, gamma, lam)
# Count variables
var_counts = tuple(core.count_vars(scope) for scope in ['pi', 'v'])
logger.log('\nNumber of parameters: \t pi: %d, \t v: %d\n' % var_counts)
# PPO objectives
ratio = tf.exp(logp - logp_old_ph) # pi(a|s) / pi_old(a|s)
min_adv = tf.where(adv_ph > 0, (1 + clip_ratio) * adv_ph,
(1 - clip_ratio) * adv_ph)
pi_loss = -tf.reduce_mean(tf.minimum(ratio * adv_ph, min_adv))
v_loss = tf.reduce_mean((ret_ph - v)**2)
# Info (useful to watch during learning)
approx_kl = tf.reduce_mean(
logp_old_ph -
logp) # a sample estimate for KL-divergence, easy to compute
approx_ent = tf.reduce_mean(
-logp) # a sample estimate for entropy, also easy to compute
clipped = tf.logical_or(ratio > (1 + clip_ratio), ratio < (1 - clip_ratio))
clipfrac = tf.reduce_mean(tf.cast(clipped, tf.float32))
# Optimizers
train_pi = MpiAdamOptimizer(
learning_rate=pi_lr).minimize(pi_loss - 0.01 * approx_ent)
train_v = MpiAdamOptimizer(learning_rate=vf_lr).minimize(v_loss)
sess = tf.Session()
sess.run(tf.global_variables_initializer())
# Sync params across processes
sess.run(sync_all_params())
# Setup model saving
logger.setup_tf_saver(sess, inputs={'x': x_ph}, outputs={'pi': pi, 'v': v})
# tf.reset_default_graph()
# restore_tf_graph(sess, '..//data//ppo//ppo_s0//simple_save')
def update():
inputs = {k: v for k, v in zip(all_phs, buf.get())}
inputs[pi_state_ph] = np.zeros((trials_per_epoch, NUM_GRU_UNITS))
inputs[v_state_ph] = np.zeros((trials_per_epoch, NUM_GRU_UNITS))
pi_l_old, v_l_old, ent = sess.run([pi_loss, v_loss, approx_ent],
feed_dict=inputs)
print(pi_l_old, v_l_old)
# Training
for i in range(train_pi_iters):
# print(f'pi:{i}')
_, kl = sess.run([train_pi, approx_kl], feed_dict=inputs)
# print(sess.run(pi_loss, feed_dict=inputs))
kl = mpi_avg(kl)
if kl > 1.5 * target_kl:
logger.log(
'Early stopping at step %d due to reaching max kl.' % i)
break
logger.store(StopIter=i)
for _ in range(train_v_iters):
# print(f'v:{_}')
sess.run(train_v, feed_dict=inputs)
# Log changes from update
import datetime
print(f'finish one batch training at {datetime.datetime.now()}')
pi_l_new, v_l_new, kl, cf = sess.run(
[pi_loss, v_loss, approx_kl, clipfrac], feed_dict=inputs)
logger.store(LossPi=pi_l_old,
LossV=v_l_old,
KL=kl,
Entropy=ent,
ClipFrac=cf,
DeltaLossPi=(pi_l_new - pi_l_old),
DeltaLossV=(v_l_new - v_l_old))
start_time = time.time()
o, r, d, ep_ret, ep_len = env.reset(), 0, False, 0, 0
# Main loop: collect experience in env and update/log each epoch
for epoch in range(epochs):
for trial in range(trials_per_epoch):
print(f'trial: {trial}')
old_a = np.array([0]).reshape(1, 1)
old_r = np.array([0]).reshape((1, 1, 1))
means = env.sample_tasks(1)[0]
action_dict = defaultdict(int)
for i in range(env.action_space.n):
action_dict[i] = 0
env.reset_task_simple(means)
task_avg = 0.0
pi_state_t = np.zeros((1, NUM_GRU_UNITS))
v_state_t = np.zeros((1, NUM_GRU_UNITS))
for step in range(steps_per_trial):
a, v_t, logp_t, pi_state_t, v_state_t = sess.run(
get_action_ops,
feed_dict={
x_ph: o.reshape(1, 1, -1),
a_ph: old_a,
rew_ph: old_r,
pi_state_ph: pi_state_t,
v_state_ph: v_state_t
})
# save and log
buf.store(o, a, r, v_t, logp_t)
logger.store(VVals=v_t)
try:
o, r, d, _ = env.step(a[0][0])
except:
print(a)
raise AssertionError
action_dict[a[0][0]] += 1
old_a = np.array(a).reshape(1, 1)
old_r = np.array([r]).reshape(1, 1, 1)
ep_ret += r
task_avg += r
ep_len += 1
terminal = d or (ep_len == max_ep_len)
if terminal or (step == local_steps_per_epoch - 1):
if not (terminal):
print(
'Warning: trajectory cut off by epoch at %d steps.'
% ep_len)
# if trajectory didn't reach terminal state, bootstrap value target
last_val = r if d else sess.run(
v, feed_dict={x_ph: o.reshape(1, -1)})
buf.finish_path(last_val)
if terminal:
# only save EpRet / EpLen if trajectory finished
logger.store(EpRet=ep_ret, EpLen=ep_len)
o, r, d, ep_ret, ep_len = env.reset(), 0, False, 0, 0
# logger.log_tabular('Epoch', epoch)
# logger.log_tabular('EpRet', with_min_and_max=True)
# logger.log_tabular('Means', means)
# logger.dump_tabular()
print(f'avg in trial {trial}: {task_avg / steps_per_trial}')
print(f'Means in trial {trial}: {means}')
print(action_dict)
# Save model
if (epoch % save_freq == 0) or (epoch == epochs - 1):
logger.save_state({'env': env}, None)
# saved_path = saver.save(sess, f"/tmp/model_epoch{epoch}.ckpt")
# print(f'Model saved in {saved_path}')
# Perform PPO update!
update()
logger.log_tabular('Epoch', epoch)
logger.log_tabular('EpRet', with_min_and_max=True)
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('VVals', with_min_and_max=True)
logger.log_tabular('TotalEnvInteracts', (epoch + 1) * steps_per_epoch)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('LossV', average_only=True)
logger.log_tabular('DeltaLossPi', average_only=True)
logger.log_tabular('DeltaLossV', average_only=True)
logger.log_tabular('Entropy', average_only=True)
logger.log_tabular('KL', average_only=True)
logger.log_tabular('ClipFrac', average_only=True)
logger.log_tabular('StopIter', average_only=True)
logger.log_tabular('Time', time.time() - start_time)
logger.dump_tabular()
def ppo(env_fn,
actor_critic=core.MLPActorCritic,
ac_kwargs=dict(),
seed=0,
steps_per_epoch=4000,
epochs=50,
gamma=0.99,
clip_ratio=0.2,
pi_lr=3e-4,
vf_lr=1e-3,
train_pi_iters=80,
train_v_iters=80,
lam=0.97,
max_ep_len=2000,
target_kl=0.01,
logger_kwargs=dict(),
save_freq=10):
global RENDER, BONUS
"""
Proximal Policy Optimization (by clipping),
with early stopping based on approximate KL
Args:
env_fn : A function which creates a copy of the environment.
The environment must satisfy the OpenAI Gym API.
actor_critic: The constructor method for a PyTorch Module with a
``step`` method, an ``act`` method, a ``pi`` module, and a ``v``
module. The ``step`` method should accept a batch of observations
and return:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``a`` (batch, act_dim) | Numpy array of actions for each
| observation.
``v`` (batch,) | Numpy array of value estimates
| for the provided observations.
``logp_a`` (batch,) | Numpy array of log probs for the
| actions in ``a``.
=========== ================ ======================================
The ``act`` method behaves the same as ``step`` but only returns ``a``.
The ``pi`` module's forward call should accept a batch of
observations and optionally a batch of actions, and return:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``pi`` N/A | Torch Distribution object, containing
| a batch of distributions describing
| the policy for the provided observations.
``logp_a`` (batch,) | Optional (only returned if batch of
| actions is given). Tensor containing
| the log probability, according to
| the policy, of the provided actions.
| If actions not given, will contain
| ``None``.
=========== ================ ======================================
The ``v`` module's forward call should accept a batch of observations
and return:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``v`` (batch,) | Tensor containing the value estimates
| for the provided observations. (Critical:
| make sure to flatten this!)
=========== ================ ======================================
ac_kwargs (dict): Any kwargs appropriate for the ActorCritic object
you provided to PPO.
seed (int): Seed for random number generators.
steps_per_epoch (int): Number of steps of interaction (state-action pairs)
for the agent and the environment in each epoch.
epochs (int): Number of epochs of interaction (equivalent to
number of policy updates) to perform.
gamma (float): Discount factor. (Always between 0 and 1.)
clip_ratio (float): Hyperparameter for clipping in the policy objective.
Roughly: how far can the new policy go from the old policy while
still profiting (improving the objective function)? The new policy
can still go farther than the clip_ratio says, but it doesn't help
on the objective anymore. (Usually small, 0.1 to 0.3.) Typically
denoted by :math:`\epsilon`.
pi_lr (float): Learning rate for policy optimizer.
vf_lr (float): Learning rate for value function optimizer.
train_pi_iters (int): Maximum number of gradient descent steps to take
on policy loss per epoch. (Early stopping may cause optimizer
to take fewer than this.)
train_v_iters (int): Number of gradient descent steps to take on
value function per epoch.
lam (float): Lambda for GAE-Lambda. (Always between 0 and 1,
close to 1.)
max_ep_len (int): Maximum length of trajectory / episode / rollout.
target_kl (float): Roughly what KL divergence we think is appropriate
between new and old policies after an update. This will get used
for early stopping. (Usually small, 0.01 or 0.05.)
logger_kwargs (dict): Keyword args for EpochLogger.
save_freq (int): How often (in terms of gap between epochs) to save
the current policy and value function.
"""
# Reachability Trainer
r_network = R_Network().to(device)
trainer = R_Network_Trainer(r_network=r_network, exp_name="random1")
episodic_memory = EpisodicMemory(embedding_shape=[EMBEDDING_DIM])
# Special function to avoid certain slowdowns from PyTorch + MPI combo.
setup_pytorch_for_mpi()
# Set up logger and save configuration
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
# Random seed
seed += 10000 * proc_id()
torch.manual_seed(seed)
np.random.seed(seed)
# Instantiate environment
env = env_fn()
observation_space = gym.spaces.Box(low=0.0, high=1.0, shape=(3, 64, 64))
action_space = gym.spaces.Discrete(3)
obs_dim = observation_space.shape
act_dim = action_space.shape
# Create actor-critic module
ac = actor_critic(observation_space, action_space, **ac_kwargs)
# Sync params across processes
sync_params(ac)
# Count variables
var_counts = tuple(core.count_vars(module) for module in [ac.pi, ac.v])
logger.log('\nNumber of parameters: \t pi: %d, \t v: %d\n' % var_counts)
# Set up experience buffer
local_steps_per_epoch = int(steps_per_epoch / num_procs())
buf = PPOBuffer(obs_dim, act_dim, local_steps_per_epoch, gamma, lam)
# Set up function for computing PPO policy loss
def compute_loss_pi(data):
obs, act, adv, logp_old = data['obs'], data['act'], data['adv'], data[
'logp']
# Policy loss
pi, logp = ac.pi(obs, act)
ratio = torch.exp(logp - logp_old)
clip_adv = torch.clamp(ratio, 1 - clip_ratio, 1 + clip_ratio) * adv
loss_pi = -(torch.min(ratio * adv, clip_adv)).mean()
# Useful extra info
approx_kl = (logp_old - logp).mean().item()
ent = pi.entropy().mean().item()
clipped = ratio.gt(1 + clip_ratio) | ratio.lt(1 - clip_ratio)
clipfrac = torch.as_tensor(clipped, dtype=torch.float32).mean().item()
pi_info = dict(kl=approx_kl, ent=ent, cf=clipfrac)
return loss_pi, pi_info
# Set up function for computing value loss
def compute_loss_v(data):
obs, ret = data['obs'], data['ret']
return ((ac.v(obs) - ret)**2).mean()
# Set up optimizers for policy and value function
pi_optimizer = Adam(ac.pi.parameters(), lr=pi_lr)
vf_optimizer = Adam(ac.v.parameters(), lr=vf_lr)
# Set up model saving
logger.setup_pytorch_saver(ac)
def update():
data = buf.get()
pi_l_old, pi_info_old = compute_loss_pi(data)
pi_l_old = pi_l_old.item()
v_l_old = compute_loss_v(data).item()
# Train policy with multiple steps of gradient descent
for i in range(train_pi_iters):
pi_optimizer.zero_grad()
loss_pi, pi_info = compute_loss_pi(data)
# Entropy bonus
loss_pi += pi_info['ent'] * 0.0021
kl = mpi_avg(pi_info['kl'])
if kl > 1.5 * target_kl:
logger.log(
'Early stopping at step %d due to reaching max kl.' % i)
break
loss_pi.backward()
mpi_avg_grads(ac.pi) # average grads across MPI processes
pi_optimizer.step()
logger.store(StopIter=i)
# Value function learning
for i in range(train_v_iters):
vf_optimizer.zero_grad()
loss_v = compute_loss_v(data)
loss_v.backward()
mpi_avg_grads(ac.v) # average grads across MPI processes
vf_optimizer.step()
# Log changes from update
kl, ent, cf = pi_info['kl'], pi_info_old['ent'], pi_info['cf']
logger.store(LossPi=pi_l_old,
LossV=v_l_old,
KL=kl,
Entropy=ent,
ClipFrac=cf,
DeltaLossPi=(loss_pi.item() - pi_l_old),
DeltaLossV=(loss_v.item() - v_l_old))
# Prepare for interaction with environment
start_time = time.time()
o, _ = env.reset()
env.render()
o = o.astype(np.float32) / 255.
o = o.transpose(2, 0, 1)
ep_ret, ep_len = 0, 0
indices = []
# Main loop: collect experience in env and update/log each epoch
for epoch in range(epochs):
for t in range(local_steps_per_epoch):
state = torch.as_tensor(o[np.newaxis, ...], dtype=torch.float32)
a, v, logp = ac.step(state)
next_o, r, d, info = env.step(a)
next_o = next_o.astype(np.float32) / 255.
d = ep_len == max_ep_len
trainer.store_new_state([next_o], [r], [d], [None])
r_network.eval()
with torch.no_grad():
state_embedding = r_network.embed_observation(
torch.FloatTensor([o]).to(device)).cpu().numpy()[0]
aggregated, _, _ = similarity_to_memory(
state_embedding, episodic_memory, r_network)
curiosity_bonus = 0.03 * (0.5 - aggregated)
if BONUS:
print(f'{curiosity_bonus:.3f}')
if curiosity_bonus > 0 or len(episodic_memory) == 0:
idx = episodic_memory.store_new_state(state_embedding)
x = int(env.map_scale * info['pose']['x'])
y = int(env.map_scale * info['pose']['y'])
if idx == len(indices):
indices.append((x, y))
else:
indices[idx] = (x, y)
r_network.train()
next_o = next_o.transpose(2, 0, 1)
ep_ret += r + curiosity_bonus
ep_len += 1
# save and log
buf.store(o, a, r, v, logp)
logger.store(VVals=v)
k = cv2.waitKey(1)
if k == ord('s'):
RENDER = 1 - RENDER
elif k == ord('b'):
BONUS = 1 - BONUS
if RENDER:
env.info['map'] = cv2.flip(env.info['map'], 0)
for index in indices:
cv2.circle(env.info['map'], index, 3, (0, 0, 255), -1)
env.info['map'] = cv2.flip(env.info['map'], 0)
env.render()
# Update obs (critical!)
o = next_o
timeout = ep_len == max_ep_len
terminal = d or timeout
epoch_ended = t == local_steps_per_epoch - 1
if terminal or epoch_ended:
if epoch_ended and not (terminal):
print('Warning: trajectory cut off by epoch at %d steps.' %
ep_len,
flush=True)
# if trajectory didn't reach terminal state, bootstrap value target
if timeout or epoch_ended:
state = torch.as_tensor(o[np.newaxis, ...],
dtype=torch.float32)
_, v, _ = ac.step(state)
else:
v = 0
buf.finish_path(v)
if terminal:
# only save EpRet / EpLen if trajectory finished
logger.store(EpRet=ep_ret, EpLen=ep_len)
print(ep_ret, ep_len, len(episodic_memory))
ep_ret, ep_len = 0, 0
o, _ = env.reset()
o = o.astype(np.float32) / 255.
o = o.transpose(2, 0, 1)
episodic_memory.reset()
indices = []
# Save model
if (epoch % save_freq == 0) or (epoch == epochs - 1):
logger.save_state({'env': env}, None)
# Perform PPO update!
if epoch > 4:
update()
# Log info about epoch
logger.log_tabular('Epoch', epoch)
logger.log_tabular('EpRet', with_min_and_max=True)
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('VVals', with_min_and_max=True)
logger.log_tabular('TotalEnvInteracts',
(epoch + 1) * steps_per_epoch)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('LossV', average_only=True)
logger.log_tabular('DeltaLossPi', average_only=True)
logger.log_tabular('DeltaLossV', average_only=True)
logger.log_tabular('Entropy', average_only=True)
logger.log_tabular('KL', average_only=True)
logger.log_tabular('ClipFrac', average_only=True)
logger.log_tabular('StopIter', average_only=True)
logger.log_tabular('Time', time.time() - start_time)
logger.dump_tabular()
else:
buf.get()
def trpo(env_fn,
actor_critic,
ac_kwargs=dict(),
seed=0,
steps_per_epoch=4000,
epochs=50,
gamma=.99,
delta=.01,
vf_lr=1e-3,
train_v_iters=80,
damping_coeff=.1,
cg_iters=10,
backtrack_iters=10,
backtrack_coeff=.8,
lam=.97,
max_ep_len=1000,
logger_kwargs=dict(),
save_freq=10,
algo="trpo"):
# LOgger tools
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
# Seed inits
seed += 10000 * proc_id()
tf.set_random_seed(seed)
np.random.seed(seed)
# Environment recreation
env = env_fn()
# Getting obs dims
obs_dim = env.observation_space.shape[0]
act_dim = env.action_space.shape[0]
ac_kwargs['action_space'] = env.action_space
# Placeholders
x_ph, a_ph = tf.placeholder( name="x_ph", shape=[None, obs_dim], dtype=tf.float32), \
tf.placeholder( name="a_ph", shape=[None, act_dim], dtype=tf.float32)
adv_ph, ret_ph, logp_old_ph = tf.placeholder( name="adv_ph", shape=[None], dtype=tf.float32), \
tf.placeholder( name="ret_ph", shape=[None], dtype=tf.float32), \
tf.placeholder( name="logp_old_ph", shape=[None], dtype=tf.float32)
pi, logp, logp_pi, info, info_phs, d_kl, v = actor_critic(
x_ph, a_ph, **ac_kwargs)
def keys_as_sorted_list(dict):
return sorted(list(dict.keys()))
def values_as_sorted_list(dict):
return [dict[k] for k in keys_as_sorted_list(dict)]
all_phs = [x_ph, a_ph, adv_ph, ret_ph, logp_old_ph
] + values_as_sorted_list(info_phs)
get_action_ops = [pi, v, logp_pi] + values_as_sorted_list(info)
# Experience buffer init
local_steps_per_epoch = int(steps_per_epoch / num_procs())
info_shapes = {k: v.shape.as_list()[1:] for k, v in info_phs.items()}
buf = GAEBuffer(obs_dim, act_dim, local_steps_per_epoch, info_shapes,
gamma, lam)
# Count variables
def get_vars(scope=''):
return [x for x in tf.trainable_variables() if scope in x.name]
def count_vars(scope=''):
v = get_vars(scope)
return sum([np.prod(var.shape.as_list()) for var in v])
var_counts = tuple(count_vars(scope) for scope in ["pi", "v"])
logger.log('\nNumber of parameters: \t pi: %d, \t v: %d\n' % var_counts)
# TRPO Losses
ratio = tf.exp(logp - logp_old_ph)
pi_loss = -tf.reduce_mean(ratio * adv_ph)
v_loss = tf.reduce_mean((ret_ph - v)**2)
# Optimizer for value function
train_vf = MpiAdamOptimizer(learning_rate=vf_lr).minimize(v_loss)
# CG solver requirements
pi_params = get_vars("pi")
# Some helpers
def flat_concat(xs):
return tf.concat([tf.reshape(x, (-1, )) for x in xs], axis=0)
def flat_grad(f, params):
return flat_concat(tf.gradients(xs=params, ys=f))
def hessian_vector_product(f, params):
g = flat_grad(f, params)
x = tf.placeholder(tf.float32, shape=g.shape)
return x, flat_grad(tf.reduce_sum(g * x), params)
def assign_params_from_flat(x, params):
flat_size = lambda p: int(np.prod(p.shape.as_list())
) # the 'int' is important for scalars
splits = tf.split(x, [flat_size(p) for p in params])
new_params = [
tf.reshape(p_new, p.shape) for p, p_new in zip(params, splits)
]
return tf.group(
[tf.assign(p, p_new) for p, p_new in zip(params, new_params)])
gradient = flat_grad(pi_loss, pi_params)
v_ph, hvp = hessian_vector_product(d_kl, pi_params)
if damping_coeff > 0:
hvp += damping_coeff * v_ph
# Symbols for getting and setting params
get_pi_params = flat_concat(pi_params)
set_pi_params = assign_params_from_flat(v_ph, pi_params)
sess = tf.Session()
sess.run(tf.global_variables_initializer())
# Sync params across processes
sess.run(sync_all_params())
# Setup model saving
logger.setup_tf_saver(sess, inputs={'x': x_ph}, outputs={'pi': pi, 'v': v})
def cg(Ax, b):
x = np.zeros_like(b)
r = b.copy()
p = r.copy()
r_dot_old = np.dot(r, r)
for _ in range(cg_iters):
z = Ax(p)
alpha = r_dot_old / (np.dot(p, z) + EPS)
x += alpha * p
r -= alpha * z
r_dot_new = np.dot(r, r)
p = r + (r_dot_new / r_dot_old) * p
r_dot_old = r_dot_new
return x
def update():
# Prepare hessian func, gradient eval
# Always so elegant haha
inputs = {k: v for k, v in zip(all_phs, buf.get())}
def mpi_avg(x):
"""Average a scalar or vector over MPI processes."""
return mpi_sum(x) / num_procs()
Hx = lambda x: mpi_avg(sess.run(hvp, feed_dict={**inputs, v_ph: x}))
g, pi_l_old, v_l_old = sess.run([gradient, pi_loss, v_loss],
feed_dict=inputs)
g, pi_l_old = mpi_avg(g), mpi_avg(pi_l_old)
# Core calculations for TRPO or NPG
x = cg(Hx, g)
alpha = np.sqrt(2 * delta / (np.dot(x, Hx(x)) + EPS)) # OK
old_params = sess.run(get_pi_params)
def set_and_eval(step):
sess.run(set_pi_params,
feed_dict={v_ph: old_params - alpha * x * step})
return mpi_avg(sess.run([d_kl, pi_loss], feed_dict=inputs))
if algo == 'npg':
# npg has no backtracking or hard kl constraint enforcement
kl, pi_l_new = set_and_eval(step=1.)
elif algo == "trpo":
for j in range(backtrack_iters):
kl, pi_l_new = set_and_eval(step=backtrack_coeff**j)
if kl <= delta and pi_l_new <= pi_l_old:
logger.log(
'Accepting new params at step %d of line search.' % j)
logger.store(BacktrackIters=j)
break
if j == backtrack_iters - 1:
logger.log('Line search failed! Keeping old params.')
logger.store(BacktrackIters=j)
kl, pi_l_new = set_and_eval(step=0.)
# Value function updates
for _ in range(train_v_iters):
sess.run(train_vf, feed_dict=inputs)
v_l_new = sess.run(v_loss, feed_dict=inputs)
# Log changes from update
logger.store(LossPi=pi_l_old,
LossV=v_l_old,
KL=kl,
DeltaLossPi=(pi_l_new - pi_l_old),
DeltaLossV=(v_l_new - v_l_old))
start_time = time.time()
o, r, d, ep_ret, ep_len = env.reset(), 0, False, 0, 0
# Main loop: collect experience in env and update/log each epoch
for epoch in range(epochs):
for t in range(local_steps_per_epoch):
agent_outs = sess.run(get_action_ops,
feed_dict={x_ph: o.reshape(1, -1)})
a, v_t, logp_t, info_t = agent_outs[0][0], agent_outs[
1], agent_outs[2], agent_outs[3:]
# Save and log
buf.store(o, a, r, v_t, logp_t, info_t)
logger.store(VVals=v_t)
o, r, d, _ = env.step(a)
ep_ret += r
ep_len += 1
terminal = d or (ep_len == max_ep_len)
if terminal or (t == local_steps_per_epoch - 1):
if not terminal:
print('Warning: trajectory cut off by epoch at %d steps.' %
ep_len)
last_val = r if d else sess.run(
v, feed_dict={x_ph: o.reshape(1, -1)})
buf.finish_path(last_val)
if terminal:
# only save EpRet / EpLen if trajectory finished
logger.store(EpRet=ep_ret, EpLen=ep_len)
o, r, d, ep_ret, ep_len = env.reset(), 0, False, 0, 0
# Save model
if (epoch % save_freq == 0) or (epoch == epochs - 1):
logger.save_state({'env': env}, None)
# Perform TRPO or NPG update!
update()
# Log info about epoch
logger.log_tabular('Epoch', epoch)
logger.log_tabular('EpRet', with_min_and_max=True)
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('VVals', with_min_and_max=True)
logger.log_tabular('TotalEnvInteracts', (epoch + 1) * steps_per_epoch)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('LossV', average_only=True)
logger.log_tabular('DeltaLossPi', average_only=True)
logger.log_tabular('DeltaLossV', average_only=True)
logger.log_tabular('KL', average_only=True)
if algo == 'trpo':
logger.log_tabular('BacktrackIters', average_only=True)
logger.log_tabular('Time', time.time() - start_time)
logger.dump_tabular()
def iac(env_config, ac_type, ac_kwargs, rb_type, rb_kwargs, gamma, lr, polyak,
batch_size, epochs, start_steps, steps_per_epoch, inc_ep, max_ep_len,
test_max_ep_len, number_of_tests_per_epoch, q_pi_sample_size, z_dim,
z_type, act_noise, test_without_state, logger_kwargs, seed):
logger = EpochLogger(**logger_kwargs)
configs = locals().copy()
configs.pop("logger")
logger.save_config(configs)
tf.set_random_seed(seed)
np.random.seed(seed)
env, test_env = make_env(env_config), make_env(env_config)
obs_dim = env.observation_space.shape[0]
act_dim = env.action_space.shape[0]
act_high = env.action_space.high
# Inputs to computation graph
x_ph, a_ph, z_ph, x2_ph, r_ph, d_ph = core.placeholders(
obs_dim, act_dim, z_dim, obs_dim, None, None)
actor_critic = core.get_iac_actor_critic(ac_type)
# Main outputs from computation graph
with tf.variable_scope('main'):
pi, q1, q2, q1_pi, q2_pi, v = actor_critic(x_ph, a_ph, z_ph,
**ac_kwargs)
# Target networks
with tf.variable_scope('target'):
_, _, _, _, _, v_targ = actor_critic(x2_ph, a_ph, z_ph, **ac_kwargs)
# Experience buffer
RB = get_replay_buffer(rb_type)
replay_buffer = RB(obs_dim, act_dim, **rb_kwargs)
# Count variables
var_counts = tuple(
core.count_vars(scope)
for scope in ['main/pi', 'main/q', 'main/v', 'main'])
print(
'\nNumber of parameters: \t pi: %d, \t q: %d, \t v: %d, \t total: %d\n'
% var_counts)
# Bellman backup for Q and V function
q_backup = tf.stop_gradient(r_ph + gamma * (1 - d_ph) * v_targ)
min_q_pi = tf.minimum(q1_pi, q2_pi)
v_backup = tf.stop_gradient(min_q_pi)
# TD3 losses
pi_loss = -tf.reduce_mean(q1_pi)
q1_loss = 0.5 * tf.reduce_mean((q1 - q_backup)**2)
q2_loss = 0.5 * tf.reduce_mean((q2 - q_backup)**2)
v_loss = 0.5 * tf.reduce_mean((v - v_backup)**2)
value_loss = q1_loss + q2_loss + v_loss
# Separate train ops for pi, q
policy_optimizer = tf.train.AdamOptimizer(learning_rate=lr)
value_optimizer = tf.train.AdamOptimizer(learning_rate=lr)
train_policy_op = policy_optimizer.minimize(pi_loss,
var_list=get_vars('main/pi'))
if ac_kwargs["pi_separate"]:
train_policy_emb_op = policy_optimizer.minimize(
pi_loss, var_list=get_vars('main/pi/emb'))
train_policy_d_op = policy_optimizer.minimize(
pi_loss, var_list=get_vars('main/pi/d'))
train_value_op = value_optimizer.minimize(value_loss,
var_list=get_vars('main/q') +
get_vars('main/v'))
# Polyak averaging for target variables
target_update = tf.group([
tf.assign(v_targ, polyak * v_targ + (1 - polyak) * v_main)
for v_main, v_targ in zip(get_vars('main'), get_vars('target'))
])
# Initializing targets to match main variables
target_init = tf.group([
tf.assign(v_targ, v_main)
for v_main, v_targ in zip(get_vars('main'), get_vars('target'))
])
sess = tf.Session()
sess.run(tf.global_variables_initializer())
sess.run(target_init)
def sample_z(size):
if z_type == "uniform":
return np.random.random_sample(size=size)
elif z_type == "gaussian":
return np.random.normal(size=size)
else:
raise Exception("z_type error")
def get_action(o, noise_scale):
pi_a = sess.run(pi,
feed_dict={
x_ph: o.reshape(1, -1),
z_ph: sample_z((1, z_dim))
})[0]
pi_a += noise_scale * np.random.randn(act_dim)
pi_a = np.clip(pi_a, 0, 1)
real_a = pi_a * act_high
return pi_a, real_a
def test_agent(n=10):
test_actions = []
for j in range(n):
test_actions_ep = []
o, r, d, ep_ret, ep_len = test_env.reset(), 0, False, 0, 0
while not (d or (ep_len == test_max_ep_len)):
# Take deterministic actions at test time (noise_scale=0)
if test_without_state:
_, real_a = get_action(np.zeros(o.shape), 0)
else:
_, real_a = get_action(o, 0)
test_actions_ep.append(real_a)
o, r, d, _ = test_env.step(real_a)
ep_ret += r
ep_len += 1
logger.store(TestEpRet=ep_ret, TestEpLen=ep_len)
test_actions.append(test_actions_ep)
return test_actions
start_time = time.time()
o, r, d, ep_ret, ep_len = env.reset(), 0, False, 0, 0
total_steps = steps_per_epoch * epochs
rewards = []
rets = []
test_rets = []
max_ret = None
# Main loop: collect experience in env and update/log each epoch
for t in range(total_steps):
"""
Until start_steps have elapsed, randomly sample actions
from a uniform distribution for better exploration. Afterwards,
use the learned policy (with some noise, via act_noise).
"""
if t > start_steps:
pi_a, real_a = get_action(o, act_noise)
else:
pi_a, real_a = env.action_space.sample()
# Step the env
o2, r, d, _ = env.step(real_a)
ep_ret += r
ep_len += 1
# Ignore the "done" signal if it comes from hitting the time
# horizon (that is, when it's an artificial terminal signal
# that isn't based on the agent's state)
d = False if ep_len == max_ep_len else d
# Store experience to replay buffer
replay_buffer.store(o, pi_a, r, o2, d)
# Super critical, easy to overlook step: make sure to update
# most recent observation!
o = o2
if d or (ep_len == max_ep_len):
for _ in range(ep_len):
batch = replay_buffer.sample_batch(batch_size)
feed_dict = {
x_ph: batch['obs1'],
x2_ph: batch['obs2'],
a_ph: batch['acts'],
r_ph: batch['rews'],
d_ph: batch['done']
}
feed_dict[z_ph] = sample_z((batch_size, z_dim))
# Policy Learning update
for key in feed_dict:
feed_dict[key] = np.repeat(feed_dict[key],
q_pi_sample_size,
axis=0)
feed_dict[z_ph] = sample_z(
(batch_size * q_pi_sample_size, z_dim))
if ac_kwargs["pi_separate"]:
if len(rewards) % 2 == 0:
outs = sess.run([pi_loss, train_policy_emb_op],
feed_dict)
else:
outs = sess.run([pi_loss, train_policy_d_op],
feed_dict)
else:
outs = sess.run([pi_loss, train_policy_op], feed_dict)
logger.store(LossPi=outs[0])
# Q-learning update
outs = sess.run([q1_loss, v_loss, q1, v, train_value_op],
feed_dict)
logger.store(LossQ=outs[0],
LossV=outs[1],
ValueQ=outs[2],
ValueV=outs[3])
logger.store(EpRet=ep_ret, EpLen=ep_len)
rewards.append(ep_ret)
o, r, d, ep_ret, ep_len = env.reset(), 0, False, 0, 0
# End of epoch wrap-up
if (t + 1) % steps_per_epoch == 0:
epoch = (t + 1) // steps_per_epoch
# Test the performance of the deterministic version of the agent.
test_actions = test_agent(number_of_tests_per_epoch)
# Log info about epoch
logger.log_tabular('Epoch', epoch)
ret = logger.log_tabular('EpRet', average_only=True)[0]
test_ret = logger.log_tabular('TestEpRet', average_only=True)[0]
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('TestEpLen', average_only=True)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('LossQ', average_only=True)
logger.log_tabular('LossV', average_only=True)
logger.log_tabular('ValueQ', average_only=True)
logger.log_tabular('ValueV', average_only=True)
logger.log_tabular('Time', time.time() - start_time)
logger.dump_tabular()
rets.append(ret)
test_rets.append(test_ret)
if max_ret is None or test_ret > max_ret:
max_ret = test_ret
best_test_actions = test_actions
max_ep_len += inc_ep
sess.run(target_update, feed_dict)
logger.save_state(
{
"rewards": rewards,
"best_test_actions": best_test_actions,
"rets": rets,
"test_rets": test_rets,
"max_ret": max_ret
}, None)
util.plot_actions(best_test_actions, act_high,
logger.output_dir + '/best_test_actions.png')
logger.log("max ret: %f" % max_ret)
