论文标题
剪切的随机方法,用于噪音重噪声的变异不平等现象
Clipped Stochastic Methods for Variational Inequalities with Heavy-Tailed Noise
论文作者
论文摘要
随机的一阶方法,例如随机外外(SEG)或随机梯度下降(SGDA),用于解决平滑的极小型问题,并且更普遍地,由于近年来,由于机器学习中对手的媒体表现的越来越多,近年来,变化不平等问题(VIP)一直引起了人们的关注。但是,尽管已知高概率收敛范围更准确地反映了随机方法的实际行为,但预期的大多数收敛结果。此外,唯一已知的高概率复杂性结果是在限制性次高斯(轻尾)噪声和有界域假设下得出的[Juditsky等,2011]。在这项工作中,我们证明了第一个高概率的复杂性结果,其对数依赖于置信水平的随机方法,用于求解单调和结构化的非单调vip,具有非辅助(重尾)噪声和无界域。在单调的情况下,我们的结果与光尾案例中最著名的结果相匹配[Juditsky等,2011],并且对于结构化的非单调问题(例如阴性共连酮,准单调单调和/或星星coccoercecerive)来说是新颖的。我们通过使用剪辑来研究SEG和SGDA来实现这些结果。此外,我们从数字上验证了许多实用GAN配方的梯度噪声是重尾的,并表明剪辑可以提高SEG/SGDA的性能。
Stochastic first-order methods such as Stochastic Extragradient (SEG) or Stochastic Gradient Descent-Ascent (SGDA) for solving smooth minimax problems and, more generally, variational inequality problems (VIP) have been gaining a lot of attention in recent years due to the growing popularity of adversarial formulations in machine learning. However, while high-probability convergence bounds are known to reflect the actual behavior of stochastic methods more accurately, most convergence results are provided in expectation. Moreover, the only known high-probability complexity results have been derived under restrictive sub-Gaussian (light-tailed) noise and bounded domain assumption [Juditsky et al., 2011]. In this work, we prove the first high-probability complexity results with logarithmic dependence on the confidence level for stochastic methods for solving monotone and structured non-monotone VIPs with non-sub-Gaussian (heavy-tailed) noise and unbounded domains. In the monotone case, our results match the best-known ones in the light-tails case [Juditsky et al., 2011], and are novel for structured non-monotone problems such as negative comonotone, quasi-strongly monotone, and/or star-cocoercive ones. We achieve these results by studying SEG and SGDA with clipping. In addition, we numerically validate that the gradient noise of many practical GAN formulations is heavy-tailed and show that clipping improves the performance of SEG/SGDA.