Abstract

We propose a novel hybrid stochastic policy gradient estimator by combining an unbiased policy gradient estimator, the REINFORCE estimator, with another biased one, an adapted SARAH estimator for policy optimization. The hybrid policy gradient estimator is shown to be biased, but has variance reduced property. Using this estimator, we develop a new Proximal Hybrid Stochastic Policy Gradient Algorithm (ProxHSPGA) to solve a composite policy optimization problem that allows us to handle constraints or regularizers on the policy parameters. We first propose a single-looped algorithm then introduce a more practical restarting variant. We prove that both algorithms can achieve the best-known trajectory complexity \(\mathcal\{O\}\left(\epsilon^\{-3\}\right)\) to attain a first-order stationary point for the composite problem which is better than existing REINFORCE/GPOMDP \(\mathcal\{O\}\left(\epsilon^\{-4\}\right)\) and SVRPG \(\mathcal\{O\}\left(\epsilon^\{-10/3\}\right)\) in the non-compos

Authors

(none)

Tags

  • Policy Gradient

Stats

  • citations0
  • S2 citationsβ€”
  • github stars0
  • HF likes0
  • heat score0.00
  • arxiv keypham2020a

Related papers