table of contents
/home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/sla_gercond.f(3) | Library Functions Manual | /home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/sla_gercond.f(3) |
NAME¶
/home/abuild/rpmbuild/BUILD/lapack-3.12.0/SRC/sla_gercond.f
SYNOPSIS¶
Functions/Subroutines¶
real function SLA_GERCOND (trans, n, a, lda, af, ldaf,
ipiv, cmode, c, info, work, iwork)
SLA_GERCOND estimates the Skeel condition number for a general matrix.
Function/Subroutine Documentation¶
real function SLA_GERCOND (character trans, integer n, real, dimension( lda, * ) a, integer lda, real, dimension( ldaf, * ) af, integer ldaf, integer, dimension( * ) ipiv, integer cmode, real, dimension( * ) c, integer info, real, dimension( * ) work, integer, dimension( * ) iwork)¶
SLA_GERCOND estimates the Skeel condition number for a general matrix.
Purpose:
!> !> SLA_GERCOND estimates the Skeel condition number of op(A) * op2(C) !> where op2 is determined by CMODE as follows !> CMODE = 1 op2(C) = C !> CMODE = 0 op2(C) = I !> CMODE = -1 op2(C) = inv(C) !> The Skeel condition number cond(A) = norminf( |inv(A)||A| ) !> is computed by computing scaling factors R such that !> diag(R)*A*op2(C) is row equilibrated and computing the standard !> infinity-norm condition number. !>
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. !>
A
!> A is REAL array, dimension (LDA,N) !> On entry, the N-by-N matrix A. !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !>
AF
!> AF is REAL array, dimension (LDAF,N) !> The factors L and U from the factorization !> A = P*L*U as computed by SGETRF. !>
LDAF
!> LDAF is INTEGER !> The leading dimension of the array AF. LDAF >= max(1,N). !>
IPIV
!> IPIV is INTEGER array, dimension (N) !> The pivot indices from the factorization A = P*L*U !> as computed by SGETRF; row i of the matrix was interchanged !> with row IPIV(i). !>
CMODE
!> CMODE is INTEGER !> Determines op2(C) in the formula op(A) * op2(C) as follows: !> CMODE = 1 op2(C) = C !> CMODE = 0 op2(C) = I !> CMODE = -1 op2(C) = inv(C) !>
C
!> C is REAL array, dimension (N) !> The vector C in the formula op(A) * op2(C). !>
INFO
!> INFO is INTEGER !> = 0: Successful exit. !> i > 0: The ith argument is invalid. !>
WORK
!> WORK is REAL array, dimension (3*N). !> Workspace. !>
IWORK
!> IWORK is INTEGER array, dimension (N). !> Workspace.2 !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 148 of file sla_gercond.f.
Author¶
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Version 3.12.0 | LAPACK |