
zpbcon.f(3) LAPACK zpbcon.f(3)
NAME
zpbcon.f 
SYNOPSIS
Functions/Subroutines
subroutine zpbcon (UPLO, N, KD, AB, LDAB, ANORM, RCOND, WORK, RWORK, INFO)
ZPBCON
Function/Subroutine Documentation
subroutine zpbcon (characterUPLO, integerN, integerKD, complex*16, dimension( ldab, * )AB,
integerLDAB, double precisionANORM, double precisionRCOND, complex*16, dimension( * )WORK,
double precision, dimension( * )RWORK, integerINFO)
ZPBCON
Purpose:
ZPBCON estimates the reciprocal of the condition number (in the
1norm) of a complex Hermitian positive definite band matrix using
the Cholesky factorization A = U**H*U or A = L*L**H computed by
ZPBTRF.
An estimate is obtained for norm(inv(A)), and the reciprocal of the
condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).
Parameters:
UPLO
UPLO is CHARACTER*1
= 'U': Upper triangular factor stored in AB;
= 'L': Lower triangular factor stored in AB.
N
N is INTEGER
The order of the matrix A. N >= 0.
KD
KD is INTEGER
The number of superdiagonals of the matrix A if UPLO = 'U',
or the number of subdiagonals if UPLO = 'L'. KD >= 0.
AB
AB is COMPLEX*16 array, dimension (LDAB,N)
The triangular factor U or L from the Cholesky factorization
A = U**H*U or A = L*L**H of the band matrix A, stored in the
first KD+1 rows of the array. The jth column of U or L is
stored in the jth column of the array AB as follows:
if UPLO ='U', AB(kd+1+ij,j) = U(i,j) for max(1,jkd)<=i<=j;
if UPLO ='L', AB(1+ij,j) = L(i,j) for j<=i<=min(n,j+kd).
LDAB
LDAB is INTEGER
The leading dimension of the array AB. LDAB >= KD+1.
ANORM
ANORM is DOUBLE PRECISION
The 1norm (or infinitynorm) of the Hermitian band matrix A.
RCOND
RCOND is DOUBLE PRECISION
The reciprocal of the condition number of the matrix A,
computed as RCOND = 1/(ANORM * AINVNM), where AINVNM is an
estimate of the 1norm of inv(A) computed in this routine.
WORK
WORK is COMPLEX*16 array, dimension (2*N)
RWORK
RWORK is DOUBLE PRECISION array, dimension (N)
INFO
INFO is INTEGER
= 0: successful exit
< 0: if INFO = i, the ith argument had an illegal value
Author:
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
November 2011
Definition at line 133 of file zpbcon.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Tue Sep 25 2012 zpbcon.f(3) 
