def td_grid(lrs):
tabular = np.zeros(23 * 4)
grid = Grid()
grid.pi_params = tabular.reshape(23, 4)
grid.softmax()
print('gridworld td')
alpha_result = []
for alpha in lrs:
estimated_v = np.zeros(23)
print('alpha = ', alpha)
# update tabular in 100 loops
for x in range(100):
s = grid.d_zero()
count = 0
while s != [5, 5] and count < 500:
a = grid.pi(s)
new_s, r = grid.P_and_R(s, a)
i = grid.get_index(s)
new_i = grid.get_index(new_s)
estimated_v[i] += alpha * (r + grid.gamma * estimated_v[new_i] - estimated_v[i])
s = new_s
count += 1
# calculate td in another 100 loops
td_list = []
for x in range(100):
s = grid.d_zero()
count = 0
while s != [5, 5] and count < 500:
a = grid.pi(s)
new_s, r = grid.P_and_R(s, a)
i = grid.get_index(s)
new_i = grid.get_index(new_s)
td_list.append((r + grid.gamma * estimated_v[new_i] - estimated_v[i]) ** 2)
s = new_s
count += 1
td_list.append(0)
print('square td = ', np.mean(np.array(td_list)))
alpha_result.append(np.mean(np.array(td_list)))
print('##########################')
return alpha_result
def reinforce_grid(lr, eps, epoch=100, searchbound=400):
estimated_rewards = np.zeros(epoch)
# theta is a representation of policy
theta = np.zeros((23, 4))
grid = Grid()
actions = grid.action
# print(epoch)
# for each episode:
for x in range(epoch):
# s ∼ d0
s = grid.d_zero()
count = 0
hist_s = []
hist_a = []
hist_r = []
grid.pi_params = estimation.softmax(theta, eps(x))
# for each time step, until s is the terminal absorbing state do
while s != [5, 5] and count < 1000:
hist_s.append(s)
a = grid.pi(s)
hist_a.append(a)
new_s, r = grid.P_and_R(s, a)
hist_r.append(r)
s = new_s
count += 1
# delta_j = 0
decay = 1
for i in range(len(hist_s)):
g = 0
gd = 1
for j in range(i, len(hist_s)):
g += gd * hist_r[j]
gd *= grid.gamma
theta[grid.get_index(hist_s[i]),
actions.index(hist_a[i])] += lr * decay * g
decay *= grid.gamma
grid.pi_params = estimation.softmax(theta, eps(x))
# grid.softmax()
grid_epi = GridEpisode(grid, step_bound=searchbound)
# print('episode: ', x, ', pi: ', grid.pi_params)
estimated_rewards[x] = grid_epi.run_all_steps()
if x == epoch - 1:
print('episode: ', x, ', reward: ', estimated_rewards[x])
# decay *= decay_rate
return estimated_rewards
def actor_critic_grid(lr, eps, epoch=100, searchbound=400):
estimated_rewards = np.zeros(epoch)
# Initialize tabular-v arbitrarily
v = np.zeros(23)
# theta is a representation of policy
theta = np.zeros((23, 4))
grid = Grid()
actions = grid.action
# for each episode:
for x in range(epoch):
# s ∼ d0
s = grid.d_zero()
count = 0
# for each time step, until s is the terminal absorbing state do
while s != [5, 5] and count < 1000:
# a ∼ π(s, ·);
grid.pi_params = estimation.softmax(theta, eps(x))
a = grid.pi(s)
# Take action a and observe r and s′;
new_s, r = grid.P_and_R(s, a)
# Critic update using TD(λ)
# e ← γλe + ∂qw(s,a)/∂qw;
delta = r + grid.gamma * v[grid.get_index(new_s)] - v[
grid.get_index(s)]
# w←w+αδev;
v[grid.get_index(s)] += lr * delta
theta[grid.get_index(s), actions.index(a)] += lr * delta
# print(theta)
s = new_s
count += 1
# using q function to estimate the reward and add it to estimated_reward
# print('episode: ', x, ', q function: ', q)
grid.pi_params = estimation.softmax(theta, eps(x))
# grid.softmax()
grid_epi = GridEpisode(grid, step_bound=searchbound)
# print('episode: ', x, ', pi: ', grid.pi_params)
estimated_rewards[x] = grid_epi.run_all_steps()
if x == 99:
print('episode: ', x, ', reward: ', estimated_rewards[x])
# decay *= decay_rate
return estimated_rewards