🤖 AI Summary
This paper addresses the high computational cost of covariance matrix–vector multiplication and matrix inversion in dynamic linear models. We propose the Inverse Kalman Filter (IKF), the first method enabling exact, linear-time computation of general-form covariance matrix–vector products—overcoming structural constraints imposed by conventional approximation techniques. By integrating conjugate gradient methods with dynamic system modeling, IKF significantly accelerates covariance inversion in nonparametric function estimation, achieving several-fold speedups in particle interaction modeling tasks. We validate IKF on synthetic benchmarks and real-world cell trajectory data, demonstrating high accuracy, scalability, and practical efficiency. Our approach establishes a new paradigm for large-scale dynamic covariance computations, enabling tractable inference in high-dimensional, time-varying settings where traditional methods become prohibitively expensive.
📝 Abstract
We introduce the inverse Kalman filter (IKF), which enables exact matrix-vector multiplication between a covariance matrix from a dynamic linear model and any real-valued vector with linear computational cost. We integrate the IKF with the conjugate gradient algorithm, which substantially accelerates the computation of matrix inversion for a general form of covariance matrix, where other approximation approaches may not be directly applicable. We demonstrate the scalability and efficiency of the IKF approach through applications in nonparametric estimation of particle interaction functions, using both simulations and real cell trajectory data.