dpocon(l) [redhat man page]

DPOCON(l)								 )								 DPOCON(l)

NAME

       DPOCON  -  estimate  the reciprocal of the condition number (in the 1-norm) of a real symmetric positive definite matrix using the Cholesky
       factorization A = U**T*U or A = L*L**T computed by DPOTRF

SYNOPSIS

       SUBROUTINE DPOCON( UPLO, N, A, LDA, ANORM, RCOND, WORK, IWORK, INFO )

	   CHARACTER	  UPLO

	   INTEGER	  INFO, LDA, N

	   DOUBLE	  PRECISION ANORM, RCOND

	   INTEGER	  IWORK( * )

	   DOUBLE	  PRECISION A( LDA, * ), WORK( * )

PURPOSE

       DPOCON estimates the reciprocal of the condition number (in the 1-norm) of a real symmetric positive definite  matrix  using  the  Cholesky
       factorization  A  = U**T*U or A = L*L**T computed by DPOTRF.  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 triangle of A is stored;
	       = 'L':  Lower triangle of A is stored.

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

       A       (input) DOUBLE PRECISION array, dimension (LDA,N)
	       The triangular factor U or L from the Cholesky factorization A = U**T*U or A = L*L**T, as computed by DPOTRF.

       LDA     (input) INTEGER
	       The leading dimension of the array A.  LDA >= max(1,N).

       ANORM   (input) DOUBLE PRECISION
	       The 1-norm (or infinity-norm) of the symmetric 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
	       1-norm 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 i-th argument had an illegal value

LAPACK version 3.0						   15 June 2000 							 DPOCON(l)

ZPOCON(l)								 )								 ZPOCON(l)

NAME

       ZPOCON - estimate the reciprocal of the condition number (in the 1-norm) of a complex Hermitian positive definite matrix using the Cholesky
       factorization A = U**H*U or A = L*L**H computed by ZPOTRF

SYNOPSIS

       SUBROUTINE ZPOCON( UPLO, N, A, LDA, ANORM, RCOND, WORK, RWORK, INFO )

	   CHARACTER	  UPLO

	   INTEGER	  INFO, LDA, N

	   DOUBLE	  PRECISION ANORM, RCOND

	   DOUBLE	  PRECISION RWORK( * )

	   COMPLEX*16	  A( LDA, * ), WORK( * )

PURPOSE

       ZPOCON estimates the reciprocal of the condition number (in the 1-norm) of a complex Hermitian positive definite matrix using the  Cholesky
       factorization  A  = U**H*U or A = L*L**H computed by ZPOTRF.  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 triangle of A is stored;
	       = 'L':  Lower triangle of A is stored.

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

       A       (input) COMPLEX*16 array, dimension (LDA,N)
	       The triangular factor U or L from the Cholesky factorization A = U**H*U or A = L*L**H, as computed by ZPOTRF.

       LDA     (input) INTEGER
	       The leading dimension of the array A.  LDA >= max(1,N).

       ANORM   (input) DOUBLE PRECISION
	       The 1-norm (or infinity-norm) of the Hermitian 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
	       1-norm of inv(A) computed in this routine.

       WORK    (workspace) COMPLEX*16 array, dimension (2*N)

       RWORK   (workspace) DOUBLE PRECISION array, dimension (N)

       INFO    (output) INTEGER
	       = 0:  successful exit
	       < 0:  if INFO = -i, the i-th argument had an illegal value

LAPACK version 3.0						   15 June 2000 							 ZPOCON(l)