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Fast optimization of common basis for matrix set through Common Singular Value Decomposition

Machine Learning 2022-04-19 v1

Abstract

SVD (singular value decomposition) is one of the basic tools of machine learning, allowing to optimize basis for a given matrix. However, sometimes we have a set of matrices {Ak}k\{A_k\}_k instead, and would like to optimize a single common basis for them: find orthogonal matrices UU, VV, such that {UTAkV}\{U^T A_k V\} set of matrices is somehow simpler. For example DCT-II is orthonormal basis of functions commonly used in image/video compression - as discussed here, this kind of basis can be quickly automatically optimized for a given dataset. While also discussed gradient descent optimization might be computationally costly, there is proposed CSVD (common SVD): fast general approach based on SVD. Specifically, we choose UU as built of eigenvectors of i(wk)q(AkAkT)p\sum_i (w_k)^q (A_k A_k^T)^p and VV of k(wk)q(AkTAk)p\sum_k (w_k)^q (A_k^T A_k)^p, where wkw_k are their weights, p,q>0p,q>0 are some chosen powers e.g. 1/2, optionally with normalization e.g. AArcTA \to A - rc^T where ri=jAij,cj=iAijr_i=\sum_j A_{ij}, c_j =\sum_i A_{ij}.

Keywords

Cite

@article{arxiv.2204.08242,
  title  = {Fast optimization of common basis for matrix set through Common Singular Value Decomposition},
  author = {Jarek Duda},
  journal= {arXiv preprint arXiv:2204.08242},
  year   = {2022}
}

Comments

4 pages, 3 figures

R2 v1 2026-06-24T10:50:48.394Z