Fast randomized algorithms for low-rank matrix approximations with applications in global comparative analysis of a class of data sets
Weiwei Xu, Weijie Shen, Wen Li, Weiguo Gao, Yingzhou Li
TL;DR
The paper introduces a randomized two-phase algorithm to compute generalized singular values for a pair of low-rank data matrices $G_1$ and $G_2$, enabling fast and accurate GSVD-based comparative analysis. By constructing orthonormal bases via randomized projections and performing GSVD on compressed matrices, it achieves substantial runtime savings while preserving accuracy in angular distances, generalized fractions, and entropy measures. The authors provide perturbation bounds linking basis approximation errors to errors in GSVD-derived quantities and validate the approach on synthetic data and real genome-scale expression datasets, including yeast, human cell-cycle, and mice macrophage data. The work offers a practical, scalable tool for genome-scale comparative analyses and highlights the method’s robustness to missing data recovery strategies.
Abstract
Generalized singular values (GSVs) play an essential role in the comparative analysis. In the real world data for comparative analysis, both data matrices are usually numerically low-rank. This paper proposes a randomized algorithm to first approximately extract bases and then calculate GSVs efficiently. The accuracy of both basis extration and comparative analysis quantities, angular distances, generalized fractions of the eigenexpression, and generalized normalized Shannon entropy, are rigursly analyzed. The proposed algorithm is applied to both synthetic data sets and the genome-scale expression data sets. Comparing to other GSVs algorithms, the proposed algorithm achieves the fastest runtime while preserving sufficient accuracy in comparative analysis.
