ColossalAI/applications/Chat/coati/models/opt/opt_rm.py

35 lines
1.1 KiB
Python

from typing import Optional
import torch.nn as nn
from transformers import OPTConfig, OPTModel
from ..base import RewardModel
class OPTRM(RewardModel):
"""
OPT Reward model.
Args:
pretrained (str): Pretrained model name or path.
config (OPTConfig): Model config.
lora_rank (int): Rank of the low-rank approximation.
lora_train_bias (str): LoRA bias training mode.
"""
def __init__(self,
pretrained: Optional[str] = None,
config: Optional[OPTConfig] = None,
lora_rank: int = 0,
lora_train_bias: str = 'none') -> None:
if pretrained is not None:
model = OPTModel.from_pretrained(pretrained)
elif config is not None:
model = OPTModel(config)
else:
model = OPTModel(OPTConfig())
value_head = nn.Linear(model.config.word_embed_proj_dim, 1)
value_head.weight.data.normal_(mean=0.0, std=1 / (model.config.word_embed_proj_dim + 1))
super().__init__(model, value_head, lora_rank, lora_train_bias)