fake_rewards = np.array([100, 100, 100])
fake_dones = np.array([1, 1, 1])
print('Testing action optimization process')
for i_action in range(NUM_ACTIONS):
fake_actions = np.array(3 * [i_action])
tf.reset_default_graph()
model = DQNModel(STATE_SHAPE, NUM_ACTIONS)
print('Optimizing for action', i_action)
with tf.Session() as sess:
sess.run(tf.global_variables_initializer())
old_preds = model.predict(sess, fake_states)
print('Old predictions:\n', old_preds)
for _ in range(100):
model.train(sess, LEARNING_RATE, fake_states, fake_target_states,
fake_actions, fake_rewards, fake_dones)
new_preds = model.predict(sess, fake_states)
print('New predictions:\n', new_preds)
print('Testing target update process')
tf.reset_default_graph()
model = DQNModel(STATE_SHAPE, NUM_ACTIONS)
with tf.Session() as sess:
sess.run(tf.global_variables_initializer())
online_preds = model.predict(sess, fake_states)
old_target_preds = model.target_predict(sess, fake_states)
class Agent:
def __init__(self,
portfolio_size,
batch_size,
max_experiences,
min_experiences,
is_eval=False):
self.portfolio_size = portfolio_size
self.action_size = 3 # sit, buy, sell
self.input_shape = (
self.portfolio_size,
self.portfolio_size,
)
self.is_eval = is_eval
#replay buffer hyperparameters
self.expReplayBuffer = {
's': [],
'a': [],
'r': [],
's2': [],
'done': []
}
self.expReplayBufferSize = 0
self.batch_size = batch_size #for replay buffer
self.max_experiences = max_experiences
self.min_experiences = min_experiences
#training hyperparameters
self.alpha = 0.5
self.gamma = 0.95
self.epsilon = 1.0
self.epsilon_min = 0.01
self.epsilon_decay = 0.05 #decay rate after every iteration
#models
self.hidden_units = [100, 50]
self.train_model = DQNModel(self.input_shape, self.hidden_units,
self.action_size,
self.portfolio_size).get_model()
self.test_model = self.get_model()
def get_model(self):
"""
Load the saved model
"""
json_file = open("models/model.json", 'r')
loaded_json_file = json_file.read()
json_file.close()
loaded_model = model_from_json(loaded_json_file)
loaded_model.load_weights("models/model.h5")
return loaded_model
def predictions_to_weights(self, pred):
"""
Helper function - Convert the model predictions to the form of weights associated with the portfolio stocks
"""
weights = np.zeros(len(pred))
raw_weights = np.argmax(pred, axis=-1)
for stock, action in enumerate(raw_weights): #should be pred
if action == 0:
weights[stock] = 0
elif action == 1:
weights[stock] = np.abs(
pred[stock][0][action]) #bcoz pred is array of arrays
else:
weights[stock] = -np.abs(
pred[stock][0][action]) #bcoz pred is array of arrays
return weights
def policy(self, state):
if self.is_eval: #testing the model, get the model predictions directly irrespective of epsilon
pred = self.test_model.predict(
np.expand_dims(state.values, 0)
) #np.expand_dims is required because we will predict 3 cases from the state position
else:
if random.random(
) <= self.epsilon: #during training, epsilon probability of choosing randomly
weights = np.random.normal(0, 1, size=(self.portfolio_size, ))
saved_sum = np.sum(weights)
weights = weights / saved_sum #sum of all weights should be 1
return weights
else:
pred = self.train_model.predict(np.expand_dims(
state.values, 0))
return self.predictions_to_weights(pred)
def weights_to_predictions(self, action_weights, rewards, Q_star):
Q = np.zeros((self.portfolio_size, self.action_size))
for i in range(self.portfolio_size):
if action_weights[i] == 0:
Q[i][0] = rewards[i] + self.gamma * np.max(Q_star[i][0])
elif action_weights[i] > 0:
Q[i][1] = rewards[i] + self.gamma * np.max(Q_star[i][1])
else:
Q[i][2] = rewards[i] + self.gamma * np.max(Q_star[i][2])
return Q
def train(self, TargetNet):
# print("Training in progress")
ids = np.random.randint(
low=0, high=len(self.expReplayBuffer['s']),
size=self.batch_size) #get batchsize exp data for training
#store the experience data in vars for easy access
# states = np.asarray([self.expReplayBuffer['s'][i] for i in ids])
# actions = np.asarray([self.expReplayBuffer['a'][i] for i in ids])
# rewards = np.asarray([self.expReplayBuffer['r'][i] for i in ids])
# states_next = np.asarray([self.expReplayBuffer['s2'][i] for i in ids])
# dones = np.asarray([self.expReplayBuffer['done'][i] for i in ids])
for i in range(len(self.expReplayBuffer['s'])):
state = self.expReplayBuffer['s'][i]
action = self.expReplayBuffer['a'][i]
reward = self.expReplayBuffer['r'][i]
state_next = self.expReplayBuffer['s2'][i]
done = self.expReplayBuffer['done'][i]
#predict the q values for the states_next using TargetNet as the variables of that net would be more stable
# print("Shape: " + str(state_next.shape))
values_next = np.max(TargetNet.predict(
np.expand_dims(state_next, axis=0)),
axis=1)
# print("Action vals")
# print(action)
# actual_values = np.where(dones, rewards, rewards+self.gamma*values_next)
Q_learned_values = self.weights_to_predictions(
action, reward, values_next)
Q_val = TargetNet.predict(np.expand_dims(state, axis=0))
#Q learing formula
Q_val = [
np.add(a * (1 - self.alpha), q * self.alpha)
for a, q in zip(Q_val, Q_learned_values)
]
#train the main model
self.train_model.fit(np.expand_dims(state, 0),
Q_val,
epochs=1,
verbose=0)
#decrease the exploration rate after every iteration
def add_experience(self, experience):
"""
add experience to the expReplayBuffer
"""
# print("Length: " + str(self.expReplayBufferSize))
if self.expReplayBufferSize >= self.max_experiences:
for key in self.expReplayBuffer.keys():
self.expReplayBuffer[key].pop(
0
) #remove an old experience to make place for a new one FIFO
for key, value in experience.items():
self.expReplayBuffer[key].append(value) #add the new experience
