CholeskyQR with Randomization and Pivoting for Tall Matrices (CQRRPT)

Fuente: arXiv
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Autori principali: Melnichenko, Maksim, Balabanov, Oleg, Murray, Riley, Demmel, James, Mahoney, Michael W., Luszczek, Piotr
Natura: Preprint
Pubblicazione: 2023
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author Melnichenko, Maksim
Balabanov, Oleg
Murray, Riley
Demmel, James
Mahoney, Michael W.
Luszczek, Piotr
author_facet Melnichenko, Maksim
Balabanov, Oleg
Murray, Riley
Demmel, James
Mahoney, Michael W.
Luszczek, Piotr
contents This paper develops and analyzes a new algorithm for QR decomposition with column pivoting (QRCP) of rectangular matrices with many more rows than columns. The algorithm carefully combines methods from randomized numerical linear algebra to accelerate pivot decisions for the input matrix and the process of decomposing the pivoted matrix into the QR form. The source of the latter improvement is CholeskyQR with randomized preconditioning. Comprehensive analysis is provided in both exact and finite-precision arithmetic to characterize the algorithm's rank-revealing properties and its numerical stability granted probabilistic assumptions of the sketching operator. An implementation of the proposed algorithm is described and made available inside the open-source RandLAPACK library, which itself relies on RandBLAS. Experiments with this implementation on an Intel Xeon Gold 6248R CPU demonstrate order-of-magnitude speedups over LAPACK's standard function for QRCP, and comparable performance to a specialized algorithm for unpivoted QR of tall matrices, which lacks the strong rank-revealing properties of the proposed method.
format Preprint
id arxiv_https___arxiv_org_abs_2311_08316
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle CholeskyQR with Randomization and Pivoting for Tall Matrices (CQRRPT)
Melnichenko, Maksim
Balabanov, Oleg
Murray, Riley
Demmel, James
Mahoney, Michael W.
Luszczek, Piotr
Numerical Analysis
This paper develops and analyzes a new algorithm for QR decomposition with column pivoting (QRCP) of rectangular matrices with many more rows than columns. The algorithm carefully combines methods from randomized numerical linear algebra to accelerate pivot decisions for the input matrix and the process of decomposing the pivoted matrix into the QR form. The source of the latter improvement is CholeskyQR with randomized preconditioning. Comprehensive analysis is provided in both exact and finite-precision arithmetic to characterize the algorithm's rank-revealing properties and its numerical stability granted probabilistic assumptions of the sketching operator. An implementation of the proposed algorithm is described and made available inside the open-source RandLAPACK library, which itself relies on RandBLAS. Experiments with this implementation on an Intel Xeon Gold 6248R CPU demonstrate order-of-magnitude speedups over LAPACK's standard function for QRCP, and comparable performance to a specialized algorithm for unpivoted QR of tall matrices, which lacks the strong rank-revealing properties of the proposed method.
title CholeskyQR with Randomization and Pivoting for Tall Matrices (CQRRPT)
topic Numerical Analysis
url https://arxiv.org/abs/2311.08316