
dppcon.f(3) LAPACK dppcon.f(3)
NAME
dppcon.f 
SYNOPSIS
Functions/Subroutines
subroutine dppcon (UPLO, N, AP, ANORM, RCOND, WORK, IWORK, INFO)
DPPCON
Function/Subroutine Documentation
subroutine dppcon (characterUPLO, integerN, double precision, dimension( * )AP, double
precisionANORM, double precisionRCOND, double precision, dimension( * )WORK, integer,
dimension( * )IWORK, integerINFO)
DPPCON
Purpose:
DPPCON estimates the reciprocal of the condition number (in the
1norm) of a real symmetric positive definite packed matrix using
the Cholesky factorization A = U**T*U or A = L*L**T computed by
DPPTRF.
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 triangle of A is stored;
= 'L': Lower triangle of A is stored.
N
N is INTEGER
The order of the matrix A. N >= 0.
AP
AP is DOUBLE PRECISION array, dimension (N*(N+1)/2)
The triangular factor U or L from the Cholesky factorization
A = U**T*U or A = L*L**T, packed columnwise in a linear
array. The jth column of U or L is stored in the array AP
as follows:
if UPLO = 'U', AP(i + (j1)*j/2) = U(i,j) for 1<=i<=j;
if UPLO = 'L', AP(i + (j1)*(2nj)/2) = L(i,j) for j<=i<=n.
ANORM
ANORM is DOUBLE PRECISION
The 1norm (or infinitynorm) of the symmetric 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 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 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 119 of file dppcon.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Tue Sep 25 2012 dppcon.f(3) 
