arrow
Return

MIXED PRECISION ITERATIVE REFINEMENT FOR LINEAR INVERSE PROBLEMS

delete2026-01-01
delete0
PRE
AI
J
James G. Nagy *
L
Lucas Onisk
DOI:10.1137/24M1703756delete
deleteOriginal
deleteOriginal request for help
deleteShare
deleteSave
Abstract

Abstract

En 中文
This study investigates the iterative refinement method applied to the solution of linear discrete inverse problems by considering its application to the Tikhonov problem in mixed precision. Previous works on mixed precision iterative refinement methods for the solution of symmetric positive definite linear systems and least-squares problems have shown regularization to be a key requirement when computing low precision factorizations. For problems that are naturally severely ill-posed, we formulate the iterates of iterative refinement in mixed precision as a filtered solution using the preconditioned Landweber method with a Tikhonov-type preconditioner. Through numerical examples simulating various mixed precision choices, we showcase the filtering properties of the method and the achievement of comparable working accuracy of discrete inverse problems (i.e., to within a few decimal places in relative error) compared to results computed in double precision as well as another approximate iterative refinement method which we use as a benchmark.
Keywords:
Key words. mixed precision
inverse problems
iterative refinement
Tikhonov regularization
preconditioned iterative methods
Landweber method

Journal

S
SIAM Journal on Matrix Analysis and Applications
IF:
1.7
Papers:
19
Citations:
0

Organization

 
 emory university
Scholars:
1.9K
Papers: 747
Citations: 0