class Trainer():
def __init__(self, model, modelParam, config, dataLoader, saveRestorer):
self.model = model
self.modelParam = modelParam
self.config = config
self.dataLoader = dataLoader
self.saveRestorer = saveRestorer
self.plotter = Plotter(self.modelParam, self.config)
return
def train(self):
for cur_epoch in range(self.model.start_epoch, self.modelParam['numbOfEpochs']):
for modeSetup in self.modelParam['modeSetups']:
mode = modeSetup[0]
is_train = modeSetup[1]
if mode == 'train':
self.model.net.train()
loss = self.run_epoch(mode, self.model, is_train, cur_epoch)
else:
with torch.no_grad():
self.model.net.eval()
loss = self.run_epoch(mode, self.model, is_train, cur_epoch)
self.plotter.update(cur_epoch, loss, mode)
self.saveRestorer.save(cur_epoch, loss, self.model)
return
def run_epoch(self, mode, model, is_train, cur_epoch):
cur_it = -1
epochTotalLoss = 0
numbOfWordsInEpoch = 0
if self.modelParam['inNotebook']:
tt = tqdm_notebook(self.dataLoader.myDataDicts[mode], desc='', leave=True, mininterval=0.01, file=sys.stdout)
else:
# tt = tqdm_notebook(self.dataLoader.myDataDicts[mode], desc='', leave=True, mininterval=0.01,file=sys.stdout)
tt = tqdm(self.dataLoader.myDataDicts[mode], desc='', leave=True, mininterval=0.01, file=sys.stdout)
for dataDict in tt:
for key in ['xTokens', 'yTokens', 'yWeights', 'vgg_fc7_features']:
dataDict[key] = dataDict[key].to(model.device)
cur_it += 1
batchTotalLoss = 0
numbOfWordsInBatch = 0
for iter in range(dataDict['numbOfTruncatedSequences']):
xTokens = dataDict['xTokens'][:, :, iter]
yTokens = dataDict['yTokens'][:, :, iter]
yWeights = dataDict['yWeights'][:, :, iter]
vgg_fc7_features = dataDict['vgg_fc7_features']
if iter==0:
logits, current_hidden_state = model.net(vgg_fc7_features, xTokens, is_train)
else:
logits, current_hidden_state_Ref = model.net(vgg_fc7_features, xTokens, is_train, current_hidden_state)
sumLoss, meanLoss = model.loss_fn(logits, yTokens, yWeights)
if mode == 'train':
model.optimizer.zero_grad()
meanLoss.backward(retain_graph=True)
model.optimizer.step()
batchTotalLoss += sumLoss.item()
numbOfWordsInBatch += yWeights.sum().item()
epochTotalLoss += batchTotalLoss
numbOfWordsInEpoch +=numbOfWordsInBatch
desc = f'{mode} | Epcohs={cur_epoch} | loss={batchTotalLoss/numbOfWordsInBatch:.4f}'
tt.set_description(desc)
tt.update()
epochLoss = epochTotalLoss/numbOfWordsInEpoch
return epochLoss
class Trainer():
def __init__(self, model, modelParam, config, saveRestorer, env):
self.model = model
self.modelParam = modelParam
self.config = config
self.saveRestorer = saveRestorer
self.env = env
self.plotter = Plotter(self.modelParam, self.config)
return
def train(self):
running_reward = 10
given_range = range(self.model.update_counter,
self.modelParam['numb_of_updates'])
if self.modelParam['inNotebook']:
tt = tqdm_notebook(given_range,
desc='',
leave=True,
mininterval=0.01,
file=sys.stdout)
else:
tt = tqdm(given_range,
desc='',
leave=True,
mininterval=0.01,
file=sys.stdout)
for update_counter in tt:
if self.modelParam['is_train']:
self.model.policyNet.train()
else:
self.model.policyNet.eval()
loss, reward = self.run_update()
reward = reward / self.modelParam["episode_batch"]
running_reward = 0.2 * reward + (1 - 0.2) * running_reward
desc = f'Update_counter={update_counter} | reward={reward:.4f} | | running_reward={running_reward:.4f}'
tt.set_description(desc)
tt.update()
if update_counter % self.modelParam['storeModelFreq'] == 0:
self.plotter.update(update_counter, running_reward)
self.saveRestorer.save(update_counter, running_reward,
self.model)
return
def run_update(self):
episodes_summary = {
'episodes_log_probs': [],
'episodes_rewards': [],
'episodes_total_reward': [],
'episodes_return': [],
}
for episode_ind in range(self.modelParam['episode_batch']):
#play episode
ep_log_probs, ep_rewards, ep_total_reward, ep_returns = self.play_episode(
)
episodes_summary['episodes_log_probs'].append(ep_log_probs)
episodes_summary['episodes_rewards'].append(ep_rewards)
episodes_summary['episodes_total_reward'].append(ep_total_reward)
episodes_summary['episodes_return'].append(ep_returns)
loss = self.gradient_update(episodes_summary)
reward = sum(episodes_summary['episodes_total_reward'])
return loss, reward
def play_episode(self):
ep_log_probs = []
ep_rewards = []
state, ep_total_reward = self.env.reset(), 0
for t in range(1, self.modelParam['max_episode_len']
): # Don't infinite loop while learning
action, log_prob = self.model.select_action(state)
state, reward, done, _ = self.env.step(action)
if self.modelParam['render']:
self.env.render()
ep_rewards.append(reward)
ep_log_probs.append(log_prob)
ep_total_reward += reward
if done:
break
#calculate return
ep_returns = []
G_t = 0
for r in ep_rewards[::-1]:
G_t = r + self.config['gamma'] * G_t
ep_returns.insert(0, G_t)
return ep_log_probs, ep_rewards, ep_total_reward, ep_returns
def gradient_update(self, episodes_summary):
policy_loss = []
#flatten the list of lists into a single list
episodes_return = [
item for sublist in episodes_summary['episodes_return']
for item in sublist
]
episodes_log_probs = [
item for sublist in episodes_summary['episodes_log_probs']
for item in sublist
]
#normalize the return to zero mean ans unit variance
eps = np.finfo(np.float32).eps.item()
episodes_return = torch.tensor(episodes_return,
device=self.model.device)
episodes_return = (episodes_return - episodes_return.mean()) / (
episodes_return.std() + eps)
for log_prob, R in zip(episodes_log_probs, episodes_return):
policy_loss.append(-log_prob *
R) #we multiply with -1 to get gradient ascent
self.model.optimizer.zero_grad()
policy_loss = torch.cat(policy_loss).sum()
policy_loss.backward()
self.model.optimizer.step()
return policy_loss.detach().cpu().item()