Change-point detection for multivariate and non-Euclidean data with local dependency
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In a sequence of multivariate observations or non-Euclidean data objects, such as networks, local dependence is common and could lead to false change-point discoveries. We propose a new way of permutation -- circular block permutation with a random starting point -- to address this problem. This permutation scheme is studied on a non-parametric change-point detection framework based on a similarity graph constructed on the observations, leading to a general framework for change-point detection for data with local dependency. Simulation studies show that this new framework retains the same level of power when there is no local dependency, while it controls type I error correctly for sequences with and without local dependency. We also derive an analytic p-value approximation under this new framework. The approximation works well for sequences with length in hundreds and above, making this approach fast-applicable for long data sequences.
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