sgbtrs()

subroutine sgbtrs	(	character	trans,
		integer	n,
		integer	kl,
		integer	ku,
		integer	nrhs,
		real, dimension( ldab, * )	ab,
		integer	ldab,
		integer, dimension( * )	ipiv,
		real, dimension( ldb, * )	b,
		integer	ldb,
		integer	info )

SGBTRS

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Purpose:

!>
!> SGBTRS solves a system of linear equations
!>    A * X = B  or  A**T * X = B
!> with a general band matrix A using the LU factorization computed
!> by SGBTRF.
!> 

Parameters

[in]	TRANS	!> TRANS is CHARACTER*1 !> Specifies the form of the system of equations. !> = 'N': A * X = B (No transpose) !> = 'T': A**T* X = B (Transpose) !> = 'C': A**T* X = B (Conjugate transpose = Transpose) !>
[in]	N	!> N is INTEGER !> The order of the matrix A. N >= 0. !>
[in]	KL	!> KL is INTEGER !> The number of subdiagonals within the band of A. KL >= 0. !>
[in]	KU	!> KU is INTEGER !> The number of superdiagonals within the band of A. KU >= 0. !>
[in]	NRHS	!> NRHS is INTEGER !> The number of right hand sides, i.e., the number of columns !> of the matrix B. NRHS >= 0. !>
[in]	AB	!> AB is REAL array, dimension (LDAB,N) !> Details of the LU factorization of the band matrix A, as !> computed by SGBTRF. U is stored as an upper triangular band !> matrix with KL+KU superdiagonals in rows 1 to KL+KU+1, and !> the multipliers used during the factorization are stored in !> rows KL+KU+2 to 2*KL+KU+1. !>
[in]	LDAB	!> LDAB is INTEGER !> The leading dimension of the array AB. LDAB >= 2*KL+KU+1. !>
[in]	IPIV	!> IPIV is INTEGER array, dimension (N) !> The pivot indices; for 1 <= i <= N, row i of the matrix was !> interchanged with row IPIV(i). !>
[in,out]	B	!> B is REAL array, dimension (LDB,NRHS) !> On entry, the right hand side matrix B. !> On exit, the solution matrix X. !>
[in]	LDB	!> LDB is INTEGER !> The leading dimension of the array B. LDB >= max(1,N). !>
[out]	INFO	!> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value !>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.