Solution of sparse rectangular systems using LSQR and CRAIG
Author(s) -
Michael A. Saunders
Publication year - 1995
Publication title -
bit numerical mathematics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.904
H-Index - 59
eISSN - 1572-9125
pISSN - 0006-3835
DOI - 10.1007/bf01739829
Subject(s) - residual , regularization (linguistics) , mathematics , linear system , extension (predicate logic) , least squares function approximation , iterative method , system of linear equations , matrix (chemical analysis) , algorithm , sparse matrix , mathematical optimization , computer science , mathematical analysis , artificial intelligence , statistics , materials science , physics , quantum mechanics , estimator , composite material , gaussian , programming language
We examine two iterative methods for solving rectangular systems of linear equations: LSQR for over-determined systemsAx ˜ b, and Craig's method for under-determined systemsAx = b. By including regularization, we extend Craig's method to incompatible systems, and observe that it solves the same damped least-squares problems as LSQR. The methods may therefore be compared on rectangular systems of arbitrary shape.
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