A1 Refereed original research article in a scientific journal

Projection-based estimators for matrix/tensor-valued data




AuthorsVirta, Joni; Nagy, Stanislav; Nordhausen, Klaus

PublisherWiley-Blackwell

Publication year2025

Journal:Scandinavian Journal of Statistics

ISSN0303-6898

eISSN1467-9469

DOIhttps://doi.org/10.1111/sjos.70021

Web address https://doi.org/10.1111/sjos.70021

Self-archived copy’s web addresshttps://research.utu.fi/converis/portal/detail/Publication/504933540


Abstract
A general approach for extending estimators to matrix- and tensor-valued data is proposed. The extension is based on using random projections to project out dimensions of a tensor and then computing a multivariate estimator for each projection. The mean of the obtained set of estimates is used as the final, joint estimate. In some basic cases, the resulting estimator can be given a closed form, and particular ones are shown to coincide with existing methodology. We derive sufficient conditions for the consistency and limiting normality of the resulting estimators under weak assumptions. In particular, limiting normality is retained as soon as the number of projections grows super-linearly in the sample size, and consistency is achieved regardless of the growth rate. Comparisons with competing methods show that the extensions prove useful in extracting components for classification and yield an efficient estimator for sufficient dimension reduction.

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Funding information in the publication
This work was supported by Research Council of Finland (Grants 335077, 347501, 353769, and 363261), Czech Science Foundation (Grant 24-10822S), the Ministry of Education, Youth and Sport of the Czech Republic (ERC CZ grant LL2407), and COST Action HiTEc (CA21163).


Last updated on 2025-24-10 at 07:43