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 2004.04057math.OC
收藏

界约束优化内点法中产生的方程组的近似解

Approximate solution of system of equations arising in interior-point methods for bound-constrained optimization

David Ek, Anders Forsgren

AI总结:

针对界约束优化内点法的牛顿系统求解权衡问题,提出基于有效/无效约束启发式估计的部分与完全近似解,及两种含部分近似解中间步骤的类牛顿法,给出理论误差界与数值验证结果。

摘要:

本文聚焦于界约束非线性优化的内点法,其中产生的非线性方程组采用牛顿法求解。直接求解牛顿系统可得到高质量解,但求解多个近似牛顿系统的计算成本更低,不过解的质量也更差,二者之间存在权衡。我们提出了牛顿系统的部分近似解和完全近似解。具体的近似解取决于对解处的有效约束和无效约束的估计。这些集合在每次迭代中通过基本启发式方法进行估计。部分近似解的计算成本较低,而完全近似解需要求解一个线性方程组,该方程组的规模由对解处无效约束的估计决定。此外,我们论证并提出了两种类牛顿方法,它们基于包含部分近似解的中间步骤。本文介绍了理论框架并给出了渐近误差界。我们还给出了数值结果,以研究近似解在理论框架内外的性能。

英文摘要:

The focus in this paper is interior-point methods for bound-constrained nonlinear optimization, where the system of nonlinear equations that arise are solved with Newton's method. There is a trade-off between solving Newton systems directly, which give high quality solutions, and solving many approximate Newton systems which are computationally less expensive but give lower quality solutions. We propose partial and full approximate solutions to the Newton systems. The specific approximate solution depends on estimates of the active and inactive constraints at the solution. These sets are at each iteration estimated by basic heuristics. The partial approximate solutions are computationally inexpensive, whereas a system of linear equations needs to be solved for the full approximate solution. The size of the system is determined by the estimate of the inactive constraints at the solution. In addition, we motivate and suggest two Newton-like approaches which are based on an intermediate step that consists of the partial approximate solutions. The theoretical setting is introduced and asymptotic error bounds are given. We also give numerical results to investigate the performance of the approximate solutions within and beyond the theoretical framework.

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。

↑