def evaluate(self, total_steps, episode_number, visualize=0):
"""
Evaluate the current agent within an experiment
:param total_steps: (int)
number of steps used in learning so far
:param episode_number: (int)
number of episodes used in learning so far
"""
random_state = np.random.get_state()
# random_state_domain = copy(self.domain.random_state)
elapsedTime = deltaT(self.start_time)
performance_return = 0.0
performance_steps = 0.0
performance_term = 0.0
performance_discounted_return = 0.0
for j in range(self.checks_per_policy):
p_ret, p_step, p_term, p_dret = self.performance_run(
total_steps, visualize=visualize > j)
performance_return += p_ret
performance_steps += p_step
performance_term += p_term
performance_discounted_return += p_dret
performance_return /= self.checks_per_policy
performance_steps /= self.checks_per_policy
performance_term /= self.checks_per_policy
performance_discounted_return /= self.checks_per_policy
self.result["learning_steps"].append(total_steps)
self.result["return"].append(performance_return)
self.result["learning_time"].append(self.elapsed_time)
self.result["num_features"].append(
self.agent.representation.features_num)
self.result["steps"].append(performance_steps)
self.result["terminated"].append(performance_term)
self.result["learning_episode"].append(episode_number)
self.result["discounted_return"].append(performance_discounted_return)
# reset start time such that performanceRuns don't count
self.start_time = clock() - elapsedTime
if total_steps > 0:
remaining = hhmmss(elapsedTime * (self.max_steps - total_steps) /
total_steps)
else:
remaining = "?"
self.logger.info(
self.performance_log_template.format(
total_steps=total_steps,
elapsed=hhmmss(elapsedTime),
remaining=remaining,
totreturn=performance_return,
steps=performance_steps,
num_feat=self.agent.representation.features_num,
))
np.random.set_state(random_state)
def traj_based_policy_evaluation(self, policy):
"""
Evaluate the current policy by simulating trajectories and update
the value function along the visited states.
"""
PE_iteration = 0
evaluation_is_accurate = False
converged_trajectories = 0
while (not evaluation_is_accurate and self.has_time()
and PE_iteration < self.max_pe_iterations):
# Generate a new episode e-greedy with the current values
max_bellman_error = 0
step = 0
s, a, terminal = self.sample_ns_na(policy, start_trajectory=True)
while not terminal and step < self.domain.episode_cap and self.has_time(
):
bellman_error, phi_s, phi_s_a = self._bellman_error(
s, a, terminal)
# Update the value function using approximate bellman backup
self.representation.weight_vec += self.alpha * bellman_error * phi_s_a
self.bellman_updates += 1
step += 1
max_bellman_error = max(max_bellman_error, abs(bellman_error))
# Discover features if the representation has the discover method
if hasattr(self.representation, "discover"):
self.representation.post_discover(phi_s, bellman_error)
s, a, terminal = self.sample_ns_na(policy, a)
# check for convergence of policy evaluation
PE_iteration += 1
if max_bellman_error < self.convergence_threshold:
converged_trajectories += 1
else:
converged_trajectories = 0
evaluation_is_accurate = (converged_trajectories >=
self.MIN_CONVERGED_TRAJECTORIES)
self.logger.info(
"PE #%d [%s]: BellmanUpdates=%d, ||Bellman_Error||=%0.4f, Features=%d"
% (
PE_iteration,
hhmmss(deltaT(self.start_time)),
self.bellman_updates,
max_bellman_error,
self.representation.features_num,
))
def policy_improvement(self, policy):
"""
Given a policy improve it by taking the greedy action in each state based
on the value function.
Returns the new policy.
"""
policyChanges = 0
i = 0
while i < self.representation.num_states_total and self.has_time():
s = self.representation.stateID2state(i)
p_actions = self.domain.possible_actions(s)
if not self.domain.is_terminal(s) and len(
self.domain.possible_actions(s)):
for a in self.domain.possible_actions(s):
self.bellman_backup(s, a, self.ns_samples, policy)
p_actions = self.domain.possible_actions(s=s)
best_action = self.representation.best_action(
s, False, p_actions)
if policy.pi(s, False, p_actions) != best_action:
policyChanges += 1
i += 1
# This will cause the policy to be copied over
policy.representation.weight = self.representation.weight.copy()
perf_return, perf_steps, perf_term, perf_disc_return = self.performance_run(
)
self.logger.info(
"PI #%d [%s]: BellmanUpdates=%d, Policy Change=%d, Return=%0.4f, Steps=%d"
% (
self.policy_improvement_iteration,
hhmmss(deltaT(self.start_time)),
self.bellman_updates,
policyChanges,
perf_return,
perf_steps,
))
# store stats
self.result["bellman_updates"].append(self.bellman_updates)
self.result["return"].append(perf_return)
self.result["planning_time"].append(deltaT(self.start_time))
self.result["num_features"].append(self.representation.features_num)
self.result["steps"].append(perf_steps)
self.result["terminated"].append(perf_term)
self.result["discounted_return"].append(perf_disc_return)
self.result["policy_improvement_iteration"].append(
self.policy_improvement_iteration)
return policy, policyChanges
def run(self,
visualize_performance=0,
visualize_learning=False,
visualize_steps=False):
"""
Run the experiment and collect statistics / generate the results
:param visualize_performance: (int)
determines whether a visualization of the steps taken in
performance runs are shown. 0 means no visualization is shown.
A value n > 0 means that only the first n performance runs for a
specific policy are shown (i.e., for n < checks_per_policy, not all
performance runs are shown)
:param visualize_learning: (boolean)
show some visualization of the learning status before each
performance evaluation (e.g. Value function)
:param visualize_steps: (boolean)
visualize all steps taken during learning
"""
self.performance_domain = deepcopy(self.domain)
self.performance_domain.performance = True
self.seed_components()
self.result = defaultdict(list)
self.result["seed"] = self.exp_id
total_steps = 0
eps_steps = 0
eps_return = 0
episode_number = 0
# show policy or value function of initial policy
if visualize_learning:
self.domain.show_learning(self.agent.representation)
# Used to bound the number of logs in the file
start_log_time = clock()
# Used to show the total time took the process
self.start_time = clock()
self.elapsed_time = 0
# do a first evaluation to get the quality of the inital policy
self.evaluate(total_steps, episode_number, visualize_performance)
self.total_eval_time = 0.0
terminal = True
while total_steps < self.max_steps:
if terminal or eps_steps >= self.domain.episode_cap:
s, terminal, p_actions = self.domain.s0()
a = self.agent.policy.pi(s, terminal, p_actions)
# Visual
if visualize_steps:
self.domain.show(a, self.agent.representation)
# Output the current status if certain amount of time has been
# passed
eps_return = 0
eps_steps = 0
episode_number += 1
# Act,Step
r, ns, terminal, np_actions = self.domain.step(a)
self._gather_transition_statistics(s, a, ns, r, learning=True)
na = self.agent.policy.pi(ns, terminal, np_actions)
total_steps += 1
eps_steps += 1
eps_return += r
# Print Current performance
if (terminal or eps_steps == self.domain.episode_cap
) and deltaT(start_log_time) > self.log_interval:
start_log_time = clock()
elapsedTime = deltaT(self.start_time)
self.logger.info(
self.log_template.format(
total_steps=total_steps,
elapsed=hhmmss(elapsedTime),
remaining=hhmmss(elapsedTime *
(self.max_steps - total_steps) /
total_steps),
totreturn=eps_return,
steps=eps_steps,
num_feat=self.agent.representation.features_num,
))
# learning
self.agent.learn(s, p_actions, a, r, ns, np_actions, na, terminal)
s, a, p_actions = ns, na, np_actions
# Visual
if visualize_steps:
self.domain.show(a, self.agent.representation)
# Check Performance
if total_steps % (self.max_steps // self.num_policy_checks) == 0:
self.elapsed_time = deltaT(
self.start_time) - self.total_eval_time
# show policy or value function
if visualize_learning:
self.domain.show_learning(self.agent.representation)
self.evaluate(total_steps, episode_number,
visualize_performance)
self.total_eval_time += (deltaT(self.start_time) -
self.elapsed_time -
self.total_eval_time)
start_log_time = clock()
# Visual
if visualize_steps:
self.domain.show(a, self.agent.representation)
self.logger.info("Total Experiment Duration %s" %
(hhmmss(deltaT(self.start_time))))
def solve_in_matrix_format(self):
# while delta_weight_vec > threshold
# 1. Gather data following an e-greedy policy
# 2. Calculate A and b estimates
# 3. calculate new_weight_vec, and delta_weight_vec
# return policy greedy w.r.t last weight_vec
self.policy = eGreedy(self.representation, epsilon=self.epsilon)
# Number of samples to be used for each policy evaluation phase. L1 in
# the Geramifard et. al. FTML 2012 paper
self.samples_num = 1000
self.start_time = clock() # Used to track the total time for solving
samples = 0
converged = False
iteration = 0
while self.has_time() and not converged:
# 1. Gather samples following an e-greedy policy
S, Actions, NS, R, T = self.collect_samples(self.samples_num)
samples += self.samples_num
# 2. Calculate A and b estimates
a_num = self.domain.num_actions
n = self.representation.features_num
discount_factor = self.domain.discount_factor
self.A = np.zeros((n * a_num, n * a_num))
self.b = np.zeros((n * a_num, 1))
for i in range(self.samples_num):
phi_s_a = self.representation.phi_sa(S[i], T[i],
Actions[i, 0]).reshape(
(-1, 1))
E_phi_ns_na = self.calculate_expected_phi_ns_na(
S[i], Actions[i, 0], self.ns_samples).reshape((-1, 1))
d = phi_s_a - discount_factor * E_phi_ns_na
self.A += np.outer(phi_s_a, d.T)
self.b += phi_s_a * R[i, 0]
# 3. calculate new_weight_vec, and delta_weight_vec
new_weight_vec, solve_time = solveLinear(regularize(self.A),
self.b)
iteration += 1
if solve_time > 1:
self.logger.info(
"#%d: Finished Policy Evaluation. Solve Time = %0.2f(s)" %
(iteration, solve_time))
weight_diff = l_norm(new_weight_vec -
self.representation.weight_vec)
converged = weight_diff < self.convergence_threshold
self.representation.weight_vec = new_weight_vec
(
perf_return,
perf_steps,
perf_term,
perf_disc_return,
) = self.performance_run()
self.logger.info(
"#%d [%s]: Samples=%d, ||weight-Change||=%0.4f, Return = %0.4f"
% (
iteration,
hhmmss(deltaT(self.start_time)),
samples,
weight_diff,
perf_return,
))
if self._visualize_mode:
self.domain.show_learning(self.representation)
# store stats
self.result["samples"].append(samples)
self.result["return"].append(perf_return)
self.result["planning_time"].append(deltaT(self.start_time))
self.result["num_features"].append(
self.representation.features_num)
self.result["steps"].append(perf_steps)
self.result["terminated"].append(perf_term)
self.result["discounted_return"].append(perf_disc_return)
self.result["iteration"].append(iteration)
if converged:
self.logger.info("Converged!")
self.log_value()
def _solve_impl(self):
"""Solve the domain MDP."""
self.start_time = clock() # Used to track the total time for solving
self.bellman_updates = 0
converged = False
PI_iteration = 0
# The policy is maintained as separate copy of the representation.
# This way as the representation is updated the policy remains intact
policy = eGreedy(deepcopy(self.representation),
epsilon=0,
deterministic=True)
a_num = self.domain.num_actions
while self.has_time() and not converged:
# Policy Improvement (Updating the representation of the value)
self.traj_based_policy_evaluation(policy)
PI_iteration += 1
# Theta can increase in size if the representation
# is expanded hence padding the weight vector with zeros
additional_dim = (self.representation.features_num -
policy.representation.features_num)
padded_theta = np.hstack(
(policy.representation.weight, np.zeros(
(a_num, additional_dim))))
# Calculate the change in the weight_vec as L2-norm
weight_diff = np.linalg.norm(padded_theta -
self.representation.weight)
converged = weight_diff < self.convergence_threshold
# Update the underlying value function of the policy
policy.representation = deepcopy(
self.representation) # self.representation
(
perf_return,
perf_steps,
perf_term,
perf_disc_return,
) = self.performance_run()
self.logger.info(
"PI #%d [%s]: BellmanUpdates=%d, ||delta-weight_vec||=%0.4f, "
"Return=%0.3f, steps=%d, features=%d" % (
PI_iteration,
hhmmss(deltaT(self.start_time)),
self.bellman_updates,
weight_diff,
perf_return,
perf_steps,
self.representation.features_num,
))
if self._visualize_mode:
self.domain.show_learning(self.representation)
# store stats
self.result["bellman_updates"].append(self.bellman_updates)
self.result["return"].append(perf_return)
self.result["planning_time"].append(deltaT(self.start_time))
self.result["num_features"].append(
self.representation.features_num)
self.result["steps"].append(perf_steps)
self.result["terminated"].append(perf_term)
self.result["discounted_return"].append(perf_disc_return)
self.result["policy_improvemnt_iteration"].append(PI_iteration)
if converged:
self.logger.info("Converged!")
self.log_value()
def policy_evaluation(self, policy):
"""
Evaluate a given policy: this is done by applying the Bellman backup over all
states until the change is less than a given threshold.
Returns: convergence status as a boolean
"""
converged = False
policy_evaluation_iteration = 0
while (not converged and self.has_time()
and policy_evaluation_iteration < self.max_pe_iterations):
policy_evaluation_iteration += 1
# Sweep The State Space
for i in range(0, self.representation.num_states_total):
# Check for solver time
if not self.has_time():
break
# Map an state ID to state
s = self.representation.stateID2state(i)
# Skip terminal states and states with no possible action
possible_actions = self.domain.possible_actions(s=s)
if self.domain.is_terminal(s) or len(possible_actions) == 0:
continue
# Apply Bellman Backup
self.bellman_backup(s, policy.pi(s, False, possible_actions),
self.ns_samples, policy)
# Update number of backups
self.bellman_updates += 1
# Check for the performance
if self.bellman_updates % self.log_interval == 0:
performance_return = self.performance_run()[0]
self.logger.info("[%s]: BellmanUpdates=%d, Return=%0.4f" %
(
hhmmss(deltaT(self.start_time)),
self.bellman_updates,
performance_return,
))
# check for convergence: L_infinity norm of the difference between the to
# the weight vector of representation
weight_diff = l_norm(policy.representation.weight -
self.representation.weight)
converged = weight_diff < self.convergence_threshold
# Log Status
self.logger.info(
"PE #%d [%s]: BellmanUpdates=%d, ||delta-weight_vec||=%0.4f" %
(
policy_evaluation_iteration,
hhmmss(deltaT(self.start_time)),
self.bellman_updates,
weight_diff,
))
# Show Plots
if self._visualize_mode:
self.domain.show_learning(self.representation)
return converged
def _solve_impl(self):
"""Solve the domain MDP."""
self.start_time = clock(
) # Used to show the total time took the process
bellman_updates = 0 # used to track the performance improvement.
converged = False
iteration = 0
num_states = self.representation.num_states_total
while self.has_time() and not converged:
iteration += 1
# Store the weight vector for comparison
prev_weight = self.representation.weight.copy()
# Sweep The State Space
for i in range(num_states):
s = self.representation.stateID2state(i)
# Sweep through possible actions
if self.domain.is_terminal(s):
continue
for a in self.domain.possible_actions(s):
self.bellman_backup(s, a, ns_samples=self.ns_samples)
bellman_updates += 1
# Create Log
if bellman_updates % self.log_interval == 0:
performance_return, _, _, _ = self.performance_run()
self._log_updates(performance_return, bellman_updates)
# check for convergence
weight_diff = l_norm(prev_weight - self.representation.weight)
converged = weight_diff < self.convergence_threshold
# log the stats
(
perf_return,
perf_steps,
perf_term,
perf_disc_return,
) = self.performance_run()
self.logger.info(
"PI #%d [%s]: BellmanUpdates=%d, ||delta-weight_vec||=%0.4f, "
"Return=%0.4f, Steps=%d" % (
iteration,
hhmmss(deltaT(self.start_time)),
bellman_updates,
weight_diff,
perf_return,
perf_steps,
))
# Show the domain and value function
if self._visualize_mode:
self.domain.show_learning(self.representation)
# store stats
self.result["bellman_updates"].append(bellman_updates)
self.result["return"].append(perf_return)
self.result["planning_time"].append(deltaT(self.start_time))
self.result["num_features"].append(
self.representation.features_num)
self.result["steps"].append(perf_steps)
self.result["terminated"].append(perf_term)
self.result["discounted_return"].append(perf_disc_return)
self.result["iteration"].append(iteration)
if converged:
self.logger.info("Converged!")
self.log_value()
def _log_updates(self, perf_return, bellman_updates):
dt = hhmmss(deltaT(self.start_tim))
self.logger.info("[%s]: BellmanUpdates=%d, Return=%0.4f" %
(dt, bellman_updates, perf_return))
def _solve_impl(self):
"""Solve the domain MDP."""
# Used to show the total time took the process
self.start_time = clock()
bellman_updates = 0
converged = False
iteration = 0
# Track the number of consequent trajectories with very small observed
# BellmanError
converged_trajectories = 0
while self.has_time() and not converged:
max_bellman_error = 0
step = 0
s, terminal, p_actions = self.domain.s0()
# Generate a new episode e-greedy with the current values
while not terminal and step < self.domain.episode_cap and self.has_time(
):
a = self.eps_greedy(s, terminal, p_actions)
bellman_error, phi_s, phi_s_a = self._bellman_error(
s, a, terminal)
# Update Parameters
self.representation.weight_vec += self.alpha * bellman_error * phi_s_a
bellman_updates += 1
step += 1
# Discover features if the representation has the discover method
if hasattr(self.representation, "discover"):
self.representation.post_discover(phi_s, bellman_error)
max_bellman_error = max(max_bellman_error, abs(bellman_error))
# Simulate new state and action on trajectory
_, s, terminal, p_actions = self.domain.step(a)
# check for convergence
iteration += 1
if max_bellman_error < self.convergence_threshold:
converged_trajectories += 1
else:
converged_trajectories = 0
(
perf_return,
perf_steps,
perf_term,
perf_disc_return,
) = self.performance_run()
converged = converged_trajectories >= self.MIN_CONVERGED_TRAJECTORIES
self.logger.info(
"PI #%d [%s]: BellmanUpdates=%d, ||Bellman_Error||=%0.4f, Return=%0.4f,"
"Steps=%d, Features=%d" % (
iteration,
hhmmss(deltaT(self.start_time)),
bellman_updates,
max_bellman_error,
perf_return,
perf_steps,
self.representation.features_num,
))
if self._visualize_mode:
self.domain.show_learning(self.representation)
# store stats
self.result["bellman_updates"].append(bellman_updates)
self.result["return"].append(perf_return)
self.result["planning_time"].append(deltaT(self.start_time))
self.result["num_features"].append(
self.representation.features_num)
self.result["steps"].append(perf_steps)
self.result["terminated"].append(perf_term)
self.result["discounted_return"].append(perf_disc_return)
self.result["iteration"].append(iteration)
if converged:
self.logger.info("Converged!")
self.log_value()