Algorithm 809: PREQN: Fortran 77 subroutines for preconditioning the conjugate gradient method

José Luis Morales, Jorge Nocedal. Algorithm 809: PREQN: Fortran 77 subroutines for preconditioning the conjugate gradient method. ACM Transactions on Mathematical Software, 27(1):83-91, 2001. [doi]

Abstract

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