SRC/zla_gbrcond_x.f(3) | Library Functions Manual | SRC/zla_gbrcond_x.f(3) |
NAME
SRC/zla_gbrcond_x.f
SYNOPSIS
Functions/Subroutines
double precision function zla_gbrcond_x (trans, n, kl, ku,
ab, ldab, afb, ldafb, ipiv, x, info, work, rwork)
ZLA_GBRCOND_X computes the infinity norm condition number of
op(A)*diag(x) for general banded matrices.
Function/Subroutine Documentation
double precision function zla_gbrcond_x (character trans, integer n, integer kl, integer ku, complex*16, dimension( ldab, * ) ab, integer ldab, complex*16, dimension( ldafb, * ) afb, integer ldafb, integer, dimension( * ) ipiv, complex*16, dimension( * ) x, integer info, complex*16, dimension( * ) work, double precision, dimension( * ) rwork)
ZLA_GBRCOND_X computes the infinity norm condition number of op(A)*diag(x) for general banded matrices.
Purpose:
!> !> ZLA_GBRCOND_X Computes the infinity norm condition number of !> op(A) * diag(X) where X is a COMPLEX*16 vector. !>
Parameters
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**H * X = B (Conjugate Transpose = Transpose) !>
N
!> N is INTEGER !> The number of linear equations, i.e., 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 COMPLEX*16 array, dimension (LDAB,N) !> On entry, the matrix A in band storage, in rows 1 to KL+KU+1. !> The j-th column of A is stored in the j-th column of the !> array AB as follows: !> AB(KU+1+i-j,j) = A(i,j) for max(1,j-KU)<=i<=min(N,j+kl) !>
LDAB
!> LDAB is INTEGER !> The leading dimension of the array AB. LDAB >= KL+KU+1. !>
AFB
!> AFB is COMPLEX*16 array, dimension (LDAFB,N) !> Details of the LU factorization of the band matrix A, as !> computed by ZGBTRF. 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. !>
LDAFB
!> LDAFB is INTEGER !> The leading dimension of the array AFB. LDAFB >= 2*KL+KU+1. !>
IPIV
!> IPIV is INTEGER array, dimension (N) !> The pivot indices from the factorization A = P*L*U !> as computed by ZGBTRF; row i of the matrix was interchanged !> with row IPIV(i). !>
X
!> X is COMPLEX*16 array, dimension (N) !> The vector X in the formula op(A) * diag(X). !>
INFO
!> INFO is INTEGER !> = 0: Successful exit. !> i > 0: The ith argument is invalid. !>
WORK
!> WORK is COMPLEX*16 array, dimension (2*N). !> Workspace. !>
RWORK
!> RWORK is DOUBLE PRECISION array, dimension (N). !> Workspace. !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 152 of file zla_gbrcond_x.f.
Author
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