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arXiv 1408.4408math.DS
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Koopman算子的数据驱动近似:扩展的动态模式分解

A Data-Driven Approximation of the Koopman Operator: Extending Dynamic Mode Decomposition

Matthew O. Williams, Ioannis G. Kevrekidis, Clarence W. Rowley

摘要:

Koopman算子是一种线性但无限维的算子,它控制着自治动力系统状态空间上标量观测量的演化,是分析和分解非线性动力系统的有力工具。在这篇手稿中,我们提出了一个数据驱动的方法近似的领先的本征值,本征函数,和模式的库普曼运营商。该方法需要一个数据集的快照对和一个字典的标量观测,但不需要明确的控制方程或相互作用的“黑匣子”积分。我们将表明,这种方法实际上是动态模式分解(DMD)的扩展,它已被用来近似Koopman特征值和模式。此外,如果提供给该方法的数据是由马尔可夫过程而不是确定性动力系统生成的,则该算法近似于Kolmogorov向后方程的本征函数,这可以被认为是“随机Koopman算子”[1]。最后,四个说明性的例子:两个突出的定量性能的方法时,无论是确定性或随机数据,和两个显示潜在的应用Koopman特征函数。

英文摘要:

The Koopman operator is a linear but infinite dimensional operator that governs the evolution of scalar observables defined on the state space of an autonomous dynamical system, and is a powerful tool for the analysis and decomposition of nonlinear dynamical systems. In this manuscript, we present a data driven method for approximating the leading eigenvalues, eigenfunctions, and modes of the Koopman operator. The method requires a data set of snapshot pairs and a dictionary of scalar observables, but does not require explicit governing equations or interaction with a "black box" integrator. We will show that this approach is, in effect, an extension of Dynamic Mode Decomposition (DMD), which has been used to approximate the Koopman eigenvalues and modes. Furthermore, if the data provided to the method are generated by a Markov process instead of a deterministic dynamical system, the algorithm approximates the eigenfunctions of the Kolmogorov backward equation, which could be considered as the "stochastic Koopman operator" [1]. Finally, four illustrative examples are presented: two that highlight the quantitative performance of the method when presented with either deterministic or stochastic data, and two that show potential applications of the Koopman eigenfunctions.

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。

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