def dump_tabular(self):
"""
Write all of the diagnostics from the current iteration.
Writes both to stdout, and to the output file.
"""
if proc_id() == 0:
vals = []
key_lens = [len(key) for key in self.log_headers]
max_key_len = max(15, max(key_lens))
keystr = '%' + '%d' % max_key_len
fmt = "| " + keystr + "s | %15s |"
n_slashes = 22 + max_key_len
print("-" * n_slashes)
for key in self.log_headers:
val = self.log_current_row.get(key, "")
valstr = "%8.3g" % val if hasattr(val, "__float__") else val
print(fmt % (key, valstr))
vals.append(val)
print("-" * n_slashes)
if self.output_file is not None:
if self.first_row:
self.output_file.write("\t".join(self.log_headers) + "\n")
self.output_file.write("\t".join(map(str, vals)) + "\n")
self.output_file.flush()
self.log_current_row.clear()
self.first_row = False
def save_state(self, state_dict, itr=None):
"""
Saves the state of an experiment.
To be clear: this is about saving *state*, not logging diagnostics.
All diagnostic logging is separate from this function. This function
will save whatever is in ``state_dict``---usually just a copy of the
environment---and the most recent parameters for the model you
previously set up saving for with ``setup_tf_saver``.
Call with any frequency you prefer. If you only want to maintain a
single state and overwrite it at each call with the most recent
version, leave ``itr=None``. If you want to keep all of the states you
save, provide unique (increasing) values for 'itr'.
Args:
state_dict (dict): Dictionary containing essential elements to
describe the current state of training.
itr: An int, or None. Current iteration of training.
"""
if proc_id() == 0:
fname = 'vars.pkl' if itr is None else 'vars%d.pkl' % itr
try:
joblib.dump(state_dict, osp.join(self.output_dir, fname))
except:
self.log('Warning: could not pickle state_dict.', color='red')
if hasattr(self, 'tf_saver_elements'):
self._tf_simple_save(itr)
def save_config(self, config):
"""
Log an experiment configuration.
Call this once at the top of your experiment, passing in all important
config vars as a dict. This will serialize the config to JSON, while
handling anything which can't be serialized in a graceful way (writing
as informative a string as possible).
Example use:
.. code-block:: python
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
"""
config_json = convert_json(config)
if self.exp_name is not None:
config_json['exp_name'] = self.exp_name
if proc_id() == 0:
output = json.dumps(config_json,
separators=(',', ':\t'),
indent=4,
sort_keys=True)
print(colorize('Saving config:\n', color='cyan', bold=True))
print(output)
with open(osp.join(self.output_dir, "config.json"), 'w') as out:
out.write(output)
def _tf_simple_save(self, itr=None):
"""
Uses simple_save to save a trained model, plus info to make it easy
to associated tensors to variables after restore.
"""
if proc_id() == 0:
assert hasattr(self, 'tf_saver_elements'), \
"First have to setup saving with self.setup_tf_saver"
fpath = 'simple_save' + ('%d' % itr if itr is not None else '')
fpath = osp.join(self.output_dir, fpath)
if osp.exists(fpath):
# simple_save refuses to be useful if fpath already exists,
# so just delete fpath if it's there.
shutil.rmtree(fpath)
tf.saved_model.simple_save(export_dir=fpath,
**self.tf_saver_elements)
joblib.dump(self.tf_saver_info, osp.join(fpath, 'model_info.pkl'))
def __init__(self,
output_dir=None,
output_fname='progress.txt',
exp_name=None):
"""
Initialize a Logger.
Args:
output_dir (string): A directory for saving results to. If
``None``, defaults to a temp directory of the form
``/tmp/experiments/somerandomnumber``.
output_fname (string): Name for the tab-separated-value file
containing metrics logged throughout a training run.
Defaults to ``progress.txt``.
exp_name (string): Experiment name. If you run multiple training
runs and give them all the same ``exp_name``, the plotter
will know to group them. (Use case: if you run the same
hyperparameter configuration with multiple random seeds, you
should give them all the same ``exp_name``.)
"""
if proc_id() == 0:
self.output_dir = output_dir or "/tmp/experiments/%i" % int(
time.time())
if osp.exists(self.output_dir):
print(
"Warning: Log dir %s already exists! Storing info there anyway."
% self.output_dir)
else:
os.makedirs(self.output_dir)
self.output_file = open(osp.join(self.output_dir, output_fname),
'w')
atexit.register(self.output_file.close)
print(
colorize("Logging data to %s" % self.output_file.name,
'green',
bold=True))
else:
self.output_dir = None
self.output_file = None
self.first_row = True
self.log_headers = []
self.log_current_row = {}
self.exp_name = exp_name
def log(self, msg, color='green'):
"""Print a colorized message to stdout."""
if proc_id() == 0:
print(colorize(msg, color, bold=True))
def vpg(env_fn,
actor_critic=core.mlp_actor_critic,
ac_kwargs=dict(),
seed=0,
steps_per_epoch=4000,
epochs=50,
gamma=0.99,
pi_lr=3e-4,
vf_lr=1e-3,
train_v_iters=80,
lam=0.97,
max_ep_len=1000,
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 VPG.
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.)
pi_lr (float): Learning rate for policy optimizer.
vf_lr (float): Learning rate for value function optimizer.
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.
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.
"""
# set up the logger
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
# generates a seed and sets it
seed += 10000 * proc_id()
tf.set_random_seed(seed)
np.random.seed(seed)
# set up the environment
env = env_fn()
# get the dimensions of the observations and action space
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)
adv_ph, ret_ph, logp_old_ph = core.placeholders(None, None, None)
# Main outputs from computation graph
pi, logp, logp_pi, v = actor_critic(x_ph, a_ph, **ac_kwargs)
# 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]
# Every step, get: action, value, and logprob
get_action_ops = [pi, v, logp_pi]
# Experience buffer
local_steps_per_epoch = int(steps_per_epoch / num_procs())
buf = VPGBuffer(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)
# VPG objectives
pi_loss = -tf.reduce_mean(logp * adv_ph)
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
# Optimizers
train_pi = MpiAdamOptimizer(learning_rate=pi_lr).minimize(pi_loss)
train_v = MpiAdamOptimizer(learning_rate=vf_lr).minimize(v_loss)
#start the session and initialize the graph variables
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():
"""
updates the policy and value function
"""
# creates inputs from placeholders and buffer
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)
# Policy gradient step
sess.run(train_pi, feed_dict=inputs)
# Value function learning
for _ in range(train_v_iters):
sess.run(train_v, feed_dict=inputs)
# Log changes from update
pi_l_new, v_l_new, kl = sess.run([pi_loss, v_loss, approx_kl],
feed_dict=inputs)
logger.store(LossPi=pi_l_old,
LossV=v_l_old,
KL=kl,
Entropy=ent,
DeltaLossPi=(pi_l_new - pi_l_old),
DeltaLossV=(v_l_new - v_l_old))
# gets the start time and resets environment and variables
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):
# get actions
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)
# perform a step and update the episode variables
o, r, d, _ = env.step(a[0])
ep_ret += r
ep_len += 1
# determine if the episode has/should be ended
terminal = d or (ep_len == max_ep_len)
# check if the episode ended or if it's reached the max amount of steps
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)
# reset environment and variables
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 VPG 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('Time', time.time() - start_time)
logger.dump_tabular()