def _find_farther_state(self, gamma):
argmin = -1
min_value = 1
rand_value = 0
best_q_star = 0
mask_0, thres = spibb.compute_mask(self.nb_states, self.nb_actions, 1,
1, [])
mask_0 = ~mask_0
rand_pi = np.ones((self.nb_states, self.nb_actions)) / self.nb_actions
for final_state in range(1, self.nb_states):
p, r = self._set_temporary_final_state(final_state)
r_reshaped = spibb_utils.get_reward_model(p, r)
rl = spibb.spibb(gamma, self.nb_states, self.nb_actions, mask_0,
mask_0, p, r_reshaped, 'default', 0, None, None,
None)
rl.fit()
v_star, q_star = spibb.policy_evaluation_exact(
rl.pi, r_reshaped, p, gamma)
v_rand, q_rand = spibb.policy_evaluation_exact(
rand_pi, r_reshaped, p, gamma)
perf_star = v_star[0]
perf_rand = v_rand[0]
if perf_star < min_value and perf_star > gamma**50:
min_value = perf_star
argmin = final_state
rand_value = perf_rand
best_q_star = q_star.copy()
avg_time_to_goal = np.log(min_value) / np.log(gamma)
avg_time_to_goal_rand = np.log(rand_value) / np.log(gamma)
print("Optimal performance : " + str(min_value))
print("Optimal average time to goal: " + str(avg_time_to_goal))
print("Random policy performance : " + str(rand_value))
print("Random policy average time to goal: " +
str(avg_time_to_goal_rand))
return argmin, min_value, best_q_star, rand_value
def _generate_softmax_policy(self, q_star, p, r_reshaped,
softmax_target_perf, reduction_factor, gamma):
temp = 2 * 10**6 # Actually starts exploring for half its value.
v = np.ones(1)
while v[0] > softmax_target_perf:
temp *= reduction_factor
pi = spibb.softmax(q_star, temp)
v, q = spibb.policy_evaluation_exact(pi, r_reshaped, p, gamma)
avg_time_to_goal = np.log(v[0]) / np.log(gamma)
print("Softmax performance : " + str(v[0]))
print("Softmax temperature : " + str(temp))
print("Softmax average time to goal: " + str(avg_time_to_goal))
return pi, v, q
def _perturb_policy(self, pi, q_star, p, r_reshaped, baseline_target_perf,
reduction_factor, gamma):
v = np.ones(1)
while v[0] > baseline_target_perf:
x = np.random.randint(self.nb_states)
pi[x, np.argmax(q_star[x, :])] *= reduction_factor
pi[x, :] /= np.sum(pi[x, :])
v, q = spibb.policy_evaluation_exact(pi, r_reshaped, p, gamma)
avg_time_to_goal = np.log(v[0]) / np.log(gamma)
print("Perturbed policy performance : " + str(v[0]))
print("Perturbed policy average time to goal: " +
str(avg_time_to_goal))
return pi, v, q
# The batch sizes:
nb_trajectories_list = [10, 20, 50, 100, 200, 500, 1000, 2000, 5000, 10000]
N_wedges = [5,7,10,15,20,30,50,70,100]
v = np.zeros(nb_states)
# Pre-compute the true reward function in function of SxA:
current_proba = maze.transition_function
garnet = garnets.Garnets(nb_states, nb_actions, 1, self_transitions=0)
garnet.transition_function = current_proba
reward_current = garnet.compute_reward()
r_reshaped = spibb_utils.get_reward_model(current_proba, reward_current)
# Compute the baseline policy performance:
pi_b_perf = spibb.policy_evaluation_exact(pi_b, r_reshaped, current_proba, gamma)[0][0]
print("baseline_perf: " + str(pi_b_perf))
# Creates a mask that is always True for classical RL and other non policy-based SPIBB algorithms
mask_0, thres = spibb.compute_mask(nb_states, nb_actions, 1, 1, [])
mask_0 = ~mask_0
pi_star = spibb.spibb(gamma, nb_states, nb_actions, mask_0, mask_0, current_proba, r_reshaped, 'default')
pi_star.fit()
pi_star_perf = spibb.policy_evaluation_exact(pi_star.pi, r_reshaped, current_proba, gamma)[0][0]
print("pi_star_perf: " + str(pi_star_perf))
# Place to save the results
filename = 'results/' + expname + '/results_' + str(index)
for nb_trajectories in nb_trajectories_list:
# Generate trajectories, both stored as trajectories and (s,a,s',r) transition samples
trajectories, batch_traj = spibb_utils.generate_batch(nb_trajectories, garnet, pi_b)
spibb_utils.prt("GENERATED A DATASET OF " + str(nb_trajectories) + " TRAJECTORIES")
# Compute the maximal likelihood model for transitions and rewards.
# NB: the true reward function can be used for ease of implementation since it is not stochastic in our environment.
# One should compute it fro mthe samples when it is stochastic.
model = modelTransitions.ModelTransitions(batch_traj, nb_states, nb_actions)
reward_model = spibb_utils.get_reward_model(model.transitions, reward_current)
policy_error = np.sum(abs(pi_b - model.policy), 1)
# print("policy l1 error:", policy_error)
print("policy divergence. mean: %05.4f; std: %05.4f" % (np.mean(policy_error), np.std(policy_error)))
perf_pi_hat = spibb.policy_evaluation_exact(model.policy, r_reshaped, current_proba, gamma)[0][0]
print("perf pi_hat: " + str(perf_pi_hat))
# Estimates the values of the baseline policy with a monte-carlo estimation from the batch data:
# q_pib_est = spibb_utils.compute_q_pib_est(gamma, nb_states, nb_actions, trajectories)
# Computes the RL policy
rl = spibb.spibb(gamma, nb_states, nb_actions, pi_b, mask_0, model.transitions, reward_model, 'default')
rl.fit()
# Evaluates the RL policy performance
perfrl = spibb.policy_evaluation_exact(rl.pi, r_reshaped, current_proba, gamma)[0][0]
print("perf RL: " + str(perfrl))
# Computes the Reward-adjusted MDP RL policy:
count_state_action = 0.00001 * np.ones((nb_states, nb_actions))
width=width,
max_turbulence=max_turbulence,
max_velocity=max_velocity)
P = wet_chicken.get_transition_function()
R = wet_chicken.get_reward_function()
r_reshaped = spibb_utils.get_reward_model(P, R)
nb_samples = 1000000
list_unbiased_wet_chicken = []
for i in range(nb_samples):
if i % 100000 == 0:
print(f'{i} out of {nb_samples} done.')
pi_sample = sample_deterministic_policy(nb_states, nb_actions, bias=False)
list_unbiased_wet_chicken.append(
spibb.policy_evaluation_exact(pi_sample, r_reshaped, P, gamma)[0][0])
df_unbiased_wet_chicken = pd.DataFrame(data=list_unbiased_wet_chicken,
columns=['Performance'])
sns.set(font_scale=2)
g = sns.FacetGrid(data=df_unbiased_wet_chicken)
g.map(sns.ecdfplot, 'Performance')
g.fig.suptitle(
f'ECDF of the performance of sampled deterministic policies on wet chicken'
)
plt.subplots_adjust(top=0.92, right=0.9, left=0.05, bottom=0.19)
### For RandomMDPs
gamma = 0.95
nb_states = 50
easter_egg = np.random.choice(potential_final_states)
# Or pick the one with the least transitions
# current_proba_sum = current_proba.reshape(-1, current_proba.shape[-1]).sum(axis=0)
# mask_easter = np.ma.array(current_proba_sum, mask=False)
# mask_easter.mask[garnet.final_state] = True
# easter_egg = np.argmin(mask_easter)
assert (garnet.final_state != easter_egg)
reward_current[:, easter_egg] = 1
current_proba[easter_egg, :, :] = 0
r_reshaped = spibb_utils.get_reward_model(current_proba,
reward_current)
# Compute optimal policy in this new environment
true_rl = spibb.spibb(gamma, nb_states, nb_actions, mask_0, mask_0,
current_proba, r_reshaped, 'default')
true_rl.fit()
pi_star_perf = spibb.policy_evaluation_exact(
true_rl.pi, r_reshaped, current_proba, gamma)[0][0]
print("Optimal perf in easter egg environment:\t\t\t" +
str(pi_star_perf))
pi_b_perf = spibb.policy_evaluation_exact(pi_b, r_reshaped,
current_proba,
gamma)[0][0]
print("Baseline perf in easter egg environment:\t\t\t" +
str(pi_b_perf))
else:
easter_egg = None
r_reshaped = spibb_utils.get_reward_model(current_proba,
reward_current)
for nb_trajectories in nb_trajectories_list:
# Generate trajectories, both stored as trajectories and (s,a,s',r) transition samples
trajectories, batch_traj = spibb_utils.generate_batch(
