We introduce a numerical methodology, referred to as the transport-based mesh-free method, which allows us to deal with continuous, discrete, or statistical models in the same unified framework, and leads us to a broad class of numerical algorithms recently implemented in a Python library (namely, CodPy). Specifically, we propose a mesh-free discretization technique based on the theory of reproducing kernels and the theory of transport mappings, in a way that is reminiscent of Lagrangian methods in computational fluid dynamics. We introduce kernel-based discretizations of a variety of differential and discrete operators (gradient, divergence, Laplacian, Leray projection, extrapolation, interpolation, polar factorization). The proposed algorithms are nonlinear in nature and enjoy quantitative error estimates based on the notion of discrepancy error, which allows one to evaluate the relevance and accuracy of, both, the given data and the numerical solutions. Our strategy is relevant when a large number of degrees of freedom are present as is the case in mathematical finance and machine learning. We consider the Fokker-Planck-Kolmogorov system (relevant for problems arising in finance and material dynamics) and a class of neural networks based on support vector machines.
翻译:引入一种数值方法,称为基于输运的无网格方法,可使我们在同一统一框架中处理连续,离散或统计模型,并引导我们进入最近在python库中实现的广泛类的数值算法(即CodPy)。具体而言,我们提出了一种基于再生核理论和输运映射理论的无网格离散化技术,这种方法类似于计算流体动力学中的拉格朗日方法。我们介绍了一类微分和离散算子(梯度,散度,拉普拉斯算子,勒雷投影,外推,插值,极坐标分解)的基于核的离散化。所提出的算法性质是非线性的,并具有基于差错误差的定量误差估计,这使得可以评估给定数据和数值解的相关性和准确性。当存在大量自由度时,我们的策略是相关的,正如在数学金融和机器学习中所示。我们考虑福克-普朗克-科尔莫戈罗夫系统(与金融和材料动力学问题相关)以及基于支持向量机的神经网络类。