arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2101.06152math.OC
收藏

余强制方程和光滑凸优化的一阶算法的理论和数值比较

Theoretical and numerical comparison of first-order algorithms for cocoercive equations and smooth convex optimization

Luis Briceño-Arias, Nelly Pustelnik

摘要:

本文对求解光滑凸优化问题和余度方程的经典一阶分裂方法进行了理论和数值比较。从理论的角度来看,我们比较收敛速度的梯度下降,向前向后,Escheman-Rachford,和道格拉斯-Rachford算法的总和最小化两个光滑的凸函数时,其中之一是强凸的。类似的比较给出了在更一般的cocoercive设置下的强单调性的存在下,我们观察到的收敛速度在优化严格优于相应的速度cocoercive方程的一些算法。我们获得了改进的利率在几种情况下,利用我们的问题的结构与文献。此外,我们指出,该算法具有最低的收敛速度依赖于强凸性和coercive参数。从数值的角度来看,我们验证了我们的理论结果,通过实施和比较以前的算法在完善的信号和图像的稀疏性逆问题。我们取代了广泛使用的$\ell_1$规范与Huber损失,我们观察到,完全接近为基础的策略具有数值和理论上的优势,相对于使用梯度步骤的方法。

英文摘要:

This paper provides a theoretical and numerical comparison of classical first-order splitting methods for solving smooth convex optimization problems and cocoercive equations. From a theoretical point of view, we compare convergence rates of gradient descent, forward-backward, Peaceman-Rachford, and Douglas-Rachford algorithms for minimizing the sum of two smooth convex functions when one of them is strongly convex. A similar comparison is given in the more general cocoercive setting under the presence of strong monotonicity and we observe that the convergence rates in optimization are strictly better than the corresponding rates for cocoercive equations for some algorithms. We obtain improved rates with respect to the literature in several instances by exploiting the structure of our problems. Moreover, we indicate which algorithm has the lowest convergence rate depending on strong convexity and cocoercive parameters. From a numerical point of view, we verify our theoretical results by implementing and comparing previous algorithms in well-established signal and image inverse problems involving sparsity. We replace the widely used $\ell_1$ norm with the Huber loss and we observe that fully proximal-based strategies have numerical and theoretical advantages with respect to methods using gradient steps.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑