ColossalAI/applications/Chat/coati/experience_maker/naive.py

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2023-03-28 12:25:36 +00:00
import torch
from coati.models.utils import compute_reward, normalize
from .base import Experience, ExperienceMaker
class NaiveExperienceMaker(ExperienceMaker):
"""
Naive experience maker.
"""
@torch.no_grad()
def make_experience(self, input_ids: torch.Tensor, **generate_kwargs) -> Experience:
self.actor.eval()
self.critic.eval()
self.initial_model.eval()
self.reward_model.eval()
sequences, attention_mask, action_mask = self.actor.generate(input_ids,
return_action_mask=True,
**generate_kwargs)
num_actions = action_mask.size(1)
action_log_probs = self.actor(sequences, num_actions, attention_mask)
base_action_log_probs = self.initial_model(sequences, num_actions, attention_mask)
value = self.critic(sequences, action_mask, attention_mask)
r = self.reward_model(sequences, attention_mask)
reward = compute_reward(r, self.kl_coef, action_log_probs, base_action_log_probs, action_mask=action_mask)
advantage = reward - value
# TODO(ver217): maybe normalize adv
if advantage.ndim == 1:
advantage = advantage.unsqueeze(-1)
return Experience(sequences, action_log_probs, value, reward, advantage, attention_mask, action_mask)