Factor Modelling for Biclustering Large-dimensional Matrix-valued Time Series

Fuente: arXiv
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Main Authors: He, Yong, Ma, Xiaoyang, Wang, Xingheng, Wang, Yalin
Format: Preprint
Published: 2025
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author He, Yong
Ma, Xiaoyang
Wang, Xingheng
Wang, Yalin
author_facet He, Yong
Ma, Xiaoyang
Wang, Xingheng
Wang, Yalin
contents A novel unsupervised learning method is proposed in this paper for biclustering large-dimensional matrix-valued time series based on an entirely new latent two-way factor structure. Each block cluster is characterized by its own row and column cluster-specific factors in addition to some common matrix factors which impact on all the matrix time series. We first estimate the global loading spaces by projecting the observation matrices onto the row or column loading space corresponding to common factors. The loading spaces for cluster-specific factors are then further recovered by projecting the observation matrices onto the orthogonal complement space of the estimated global loading spaces. To identify the latent row/column clusters simultaneously for matrix-valued time series, we provide a $K$-means algorithm based on the estimated row/column factor loadings of the cluster-specific weak factors. Theoretically, we derive faster convergence rates for global loading matrices than those of the state-of-the-art methods available in the literature under mild conditions. We also propose an one-pass eigenvalue-ratio method to estimate the numbers of global and cluster-specific factors. The consistency with explicit convergence rates is also established for the estimators of the local loading matrices, the factor numbers and the latent cluster memberships. Numerical experiments with both simulated data as well as a real data example are also reported to illustrate the usefulness of our proposed method.
format Preprint
id arxiv_https___arxiv_org_abs_2502_06397
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Factor Modelling for Biclustering Large-dimensional Matrix-valued Time Series
He, Yong
Ma, Xiaoyang
Wang, Xingheng
Wang, Yalin
Methodology
A novel unsupervised learning method is proposed in this paper for biclustering large-dimensional matrix-valued time series based on an entirely new latent two-way factor structure. Each block cluster is characterized by its own row and column cluster-specific factors in addition to some common matrix factors which impact on all the matrix time series. We first estimate the global loading spaces by projecting the observation matrices onto the row or column loading space corresponding to common factors. The loading spaces for cluster-specific factors are then further recovered by projecting the observation matrices onto the orthogonal complement space of the estimated global loading spaces. To identify the latent row/column clusters simultaneously for matrix-valued time series, we provide a $K$-means algorithm based on the estimated row/column factor loadings of the cluster-specific weak factors. Theoretically, we derive faster convergence rates for global loading matrices than those of the state-of-the-art methods available in the literature under mild conditions. We also propose an one-pass eigenvalue-ratio method to estimate the numbers of global and cluster-specific factors. The consistency with explicit convergence rates is also established for the estimators of the local loading matrices, the factor numbers and the latent cluster memberships. Numerical experiments with both simulated data as well as a real data example are also reported to illustrate the usefulness of our proposed method.
title Factor Modelling for Biclustering Large-dimensional Matrix-valued Time Series
topic Methodology
url https://arxiv.org/abs/2502.06397