DPBCON(3)
estimates the reciprocal of the condition number (in the 1norm) of a real symmetric positive definite band matrix using the Cholesky factorization A = U**T*U or A = L*L**T computed by DPBTRF
SYNOPSIS
 SUBROUTINE DPBCON(

UPLO, N, KD, AB, LDAB, ANORM, RCOND, WORK,
IWORK, INFO )

CHARACTER
UPLO

INTEGER
INFO, KD, LDAB, N

DOUBLE
PRECISION ANORM, RCOND

INTEGER
IWORK( * )

DOUBLE
PRECISION AB( LDAB, * ), WORK( * )
PURPOSE
DPBCON estimates the reciprocal of the condition number (in the
1norm) of a real symmetric positive definite band matrix using the
Cholesky factorization A = U**T*U or A = L*L**T computed by DPBTRF.
An estimate is obtained for norm(inv(A)), and the reciprocal of the
condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).
ARGUMENTS
 UPLO (input) CHARACTER*1

= 'U': Upper triangular factor stored in AB;
= 'L': Lower triangular factor stored in AB.
 N (input) INTEGER

The order of the matrix A. N >= 0.
 KD (input) INTEGER

The number of superdiagonals of the matrix A if UPLO = 'U',
or the number of subdiagonals if UPLO = 'L'. KD >= 0.
 AB (input) DOUBLE PRECISION array, dimension (LDAB,N)

The triangular factor U or L from the Cholesky factorization
A = U**T*U or A = L*L**T 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 (input) INTEGER

The leading dimension of the array AB. LDAB >= KD+1.
 ANORM (input) DOUBLE PRECISION

The 1norm (or infinitynorm) of the symmetric band matrix A.
 RCOND (output) 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 (workspace) DOUBLE PRECISION array, dimension (3*N)

 IWORK (workspace) INTEGER array, dimension (N)

 INFO (output) INTEGER

= 0: successful exit
< 0: if INFO = i, the ith argument had an illegal value