table of contents
/home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/dgbcon.f(3) | Library Functions Manual | /home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/dgbcon.f(3) |
NAME¶
/home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/dgbcon.f
SYNOPSIS¶
Functions/Subroutines¶
subroutine DGBCON (norm, n, kl, ku, ab, ldab, ipiv, anorm,
rcond, work, iwork, info)
DGBCON
Function/Subroutine Documentation¶
subroutine DGBCON (character norm, integer n, integer kl, integer ku, double precision, dimension( ldab, * ) ab, integer ldab, integer, dimension( * ) ipiv, double precision anorm, double precision rcond, double precision, dimension( * ) work, integer, dimension( * ) iwork, integer info)¶
DGBCON
Purpose:
!> !> DGBCON estimates the reciprocal of the condition number of a real !> general band matrix A, in either the 1-norm or the infinity-norm, !> using the LU factorization computed by DGBTRF. !> !> An estimate is obtained for norm(inv(A)), and the reciprocal of the !> condition number is computed as !> RCOND = 1 / ( norm(A) * norm(inv(A)) ). !>
Parameters
NORM
!> NORM is CHARACTER*1 !> Specifies whether the 1-norm condition number or the !> infinity-norm condition number is required: !> = '1' or 'O': 1-norm; !> = 'I': Infinity-norm. !>
N
!> N is INTEGER !> The order of the matrix A. N >= 0. !>
KL
!> KL is INTEGER !> The number of subdiagonals within the band of A. KL >= 0. !>
KU
!> KU is INTEGER !> The number of superdiagonals within the band of A. KU >= 0. !>
AB
!> AB is DOUBLE PRECISION array, dimension (LDAB,N) !> Details of the LU factorization of the band matrix A, as !> computed by DGBTRF. 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. !>
LDAB
!> LDAB is INTEGER !> The leading dimension of the array AB. LDAB >= 2*KL+KU+1. !>
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). !>
ANORM
!> ANORM is DOUBLE PRECISION !> If NORM = '1' or 'O', the 1-norm of the original matrix A. !> If NORM = 'I', the infinity-norm of the original matrix A. !>
RCOND
!> RCOND is DOUBLE PRECISION !> The reciprocal of the condition number of the matrix A, !> computed as RCOND = 1/(norm(A) * norm(inv(A))). !>
WORK
!> WORK is DOUBLE PRECISION array, dimension (3*N) !>
IWORK
!> IWORK is INTEGER array, dimension (N) !>
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.
Definition at line 144 of file dgbcon.f.
Author¶
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Version 3.12.0 | LAPACK |