论文标题
桥接传统和机器学习的算法解决PDE:随机功能方法
Bridging Traditional and Machine Learning-based Algorithms for Solving PDEs: The Random Feature Method
论文作者
论文摘要
科学计算中最古老,研究最多的主题之一是解决部分微分方程(PDE)的算法。已经提出了一长串数值方法,并成功地用于各种应用程序。近年来,深度学习方法表明了它们对传统方法失败的高维PDE的优势。但是,对于低维问题,尚不清楚这些方法是否比传统算法作为直接求解器具有真正的优势。在这项工作中,我们提出了用于求解PDE的随机特征方法(RFM),这是传统和基于机器学习算法之间的自然桥梁。 RFM基于众所周知的思想的组合:1。使用随机特征函数表示近似解决方案; 2。照顾PDE的搭配方法; 3。处理边界条件的惩罚方法,这使我们能够在同一基础上处理边界条件和PDE。我们发现添加几个其他组件至关重要,包括多尺度表示并重新缩放损失函数中的权重。我们证明该方法具有光谱的准确性,并且可以在准确性和效率方面与传统求解器竞争。此外,我们发现RFM特别适合复杂几何形状的复杂问题,在这些几何形状中,传统和基于机器的算法都遇到困难。
One of the oldest and most studied subject in scientific computing is algorithms for solving partial differential equations (PDEs). A long list of numerical methods have been proposed and successfully used for various applications. In recent years, deep learning methods have shown their superiority for high-dimensional PDEs where traditional methods fail. However, for low dimensional problems, it remains unclear whether these methods have a real advantage over traditional algorithms as a direct solver. In this work, we propose the random feature method (RFM) for solving PDEs, a natural bridge between traditional and machine learning-based algorithms. RFM is based on a combination of well-known ideas: 1. representation of the approximate solution using random feature functions; 2. collocation method to take care of the PDE; 3. the penalty method to treat the boundary conditions, which allows us to treat the boundary condition and the PDE in the same footing. We find it crucial to add several additional components including multi-scale representation and rescaling the weights in the loss function. We demonstrate that the method exhibits spectral accuracy and can compete with traditional solvers in terms of both accuracy and efficiency. In addition, we find that RFM is particularly suited for complex problems with complex geometry, where both traditional and machine learning-based algorithms encounter difficulties.