dgesc2()

subroutine dgesc2	(	integer	n,
		double precision, dimension( lda, * )	a,
		integer	lda,
		double precision, dimension( * )	rhs,
		integer, dimension( * )	ipiv,
		integer, dimension( * )	jpiv,
		double precision	scale )

DGESC2 solves a system of linear equations using the LU factorization with complete pivoting computed by sgetc2.

Download DGESC2 + dependencies [TGZ] [ZIP] [TXT]

Purpose:

!>
!> DGESC2 solves a system of linear equations
!>
!>           A * X = scale* RHS
!>
!> with a general N-by-N matrix A using the LU factorization with
!> complete pivoting computed by DGETC2.
!> 

Parameters

[in]	N	!> N is INTEGER !> The order of the matrix A. !>
[in]	A	!> A is DOUBLE PRECISION array, dimension (LDA,N) !> On entry, the LU part of the factorization of the n-by-n !> matrix A computed by DGETC2: A = P * L * U * Q !>
[in]	LDA	!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1, N). !>
[in,out]	RHS	!> RHS is DOUBLE PRECISION array, dimension (N). !> On entry, the right hand side vector b. !> On exit, the solution vector X. !>
[in]	IPIV	!> IPIV is INTEGER array, dimension (N). !> The pivot indices; for 1 <= i <= N, row i of the !> matrix has been interchanged with row IPIV(i). !>
[in]	JPIV	!> JPIV is INTEGER array, dimension (N). !> The pivot indices; for 1 <= j <= N, column j of the !> matrix has been interchanged with column JPIV(j). !>
[out]	SCALE	!> SCALE is DOUBLE PRECISION !> On exit, SCALE contains the scale factor. SCALE is chosen !> 0 <= SCALE <= 1 to prevent overflow in the solution. !>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Contributors:

Bo Kagstrom and Peter Poromaa, Department of Computing Science, Umea University, S-901 87 Umea, Sweden.