torchtune.rlhf

Components and losses for RLHF algorithms like PPO and DPO.

estimate_advantages	Estimates the advantages and returns for the PPO algorithm using Generalized Advantage Estimation https://arxiv.org/pdf/1506.02438.pdf
get_rewards_ppo	Calculates PPO rewards for the given scores, logprobs, and reference logprobs.
truncate_sequence_at_first_stop_token	Truncates sequence(s) after the first stop token and pads with fill_value.
loss.PPOLoss	Proximal Policy Optimization (PPO) Loss module.
loss.DPOLoss	Direct Preference Optimization (DPO) Loss module: https://arxiv.org/abs/2305.18290 Simply stated from the paper:
loss.RSOLoss	Statistical Rejection Sampling Optimization (RSO) or "hinge" loss module: https://arxiv.org/abs/2309.06657.
loss.SimPOLoss	SimPO: Simple Preference Optimization with a Reference-Free Reward: https://arxiv.org/abs/2405.14734.