table of contents
other versions
- jessie 3.5.0-4
- jessie-backports 3.7.0-1~bpo8+1
- stretch 3.7.0-2
dpbcon.f(3) | LAPACK | dpbcon.f(3) |
NAME¶
dpbcon.f -SYNOPSIS¶
Functions/Subroutines¶
subroutine dpbcon (UPLO, N, KD, AB, LDAB, ANORM, RCOND, WORK, IWORK, INFO)
Function/Subroutine Documentation¶
subroutine dpbcon (characterUPLO, integerN, integerKD, double precision, dimension( ldab, * )AB, integerLDAB, double precisionANORM, double precisionRCOND, double precision, dimension( * )WORK, integer, dimension( * )IWORK, integerINFO)¶
DPBCON Purpose:DPBCON estimates the reciprocal of the condition number (in the 1-norm) 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))).
UPLO
Author:
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 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 j-th column of U or L is stored in the j-th column of the array AB as follows: if UPLO ='U', AB(kd+1+i-j,j) = U(i,j) for max(1,j-kd)<=i<=j; if UPLO ='L', AB(1+i-j,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 1-norm (or infinity-norm) of the symmetric 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 1-norm of inv(A) computed in this routine.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
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
November 2011
Definition at line 132 of file dpbcon.f.
Author¶
Generated automatically by Doxygen for LAPACK from the source code.Wed Oct 15 2014 | Version 3.4.2 |