zgtcon.f(3) [centos man page]

zgtcon.f(3)							      LAPACK							       zgtcon.f(3)

NAME

       zgtcon.f -

SYNOPSIS

   Functions/Subroutines
       subroutine zgtcon (NORM, N, DL, D, DU, DU2, IPIV, ANORM, RCOND, WORK, INFO)
	   ZGTCON

Function/Subroutine Documentation
   subroutine zgtcon (characterNORM, integerN, complex*16, dimension( * )DL, complex*16, dimension( * )D, complex*16, dimension( * )DU,
       complex*16, dimension( * )DU2, integer, dimension( * )IPIV, double precisionANORM, double precisionRCOND, complex*16, dimension( * )WORK,
       integerINFO)
       ZGTCON

       Purpose:

	    ZGTCON estimates the reciprocal of the condition number of a complex
	    tridiagonal matrix A using the LU factorization as computed by
	    ZGTTRF.

	    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:
	   NORM

		     NORM is CHARACTER*1
		     Specifies whether the 1-norm condition number or the
		     infinity-norm condition number is required:
		     = '1' or 'O':  1-norm;
		     = 'I':	    Infinity-norm.

	   N

		     N is INTEGER
		     The order of the matrix A.  N >= 0.

	   DL

		     DL is COMPLEX*16 array, dimension (N-1)
		     The (n-1) multipliers that define the matrix L from the
		     LU factorization of A as computed by ZGTTRF.

	   D

		     D is COMPLEX*16 array, dimension (N)
		     The n diagonal elements of the upper triangular matrix U from
		     the LU factorization of A.

	   DU

		     DU is COMPLEX*16 array, dimension (N-1)
		     The (n-1) elements of the first superdiagonal of U.

	   DU2

		     DU2 is COMPLEX*16 array, dimension (N-2)
		     The (n-2) elements of the second superdiagonal of U.

	   IPIV

		     IPIV is INTEGER array, dimension (N)
		     The pivot indices; for 1 <= i <= n, row i of the matrix was
		     interchanged with row IPIV(i).  IPIV(i) will always be either
		     i or i+1; IPIV(i) = i indicates a row interchange was not
		     required.

	   ANORM

		     ANORM is DOUBLE PRECISION
		     If NORM = '1' or 'O', the 1-norm of the original matrix A.
		     If NORM = 'I', the infinity-norm of the original 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 COMPLEX*16 array, dimension (2*N)

	   INFO

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

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   September 2012

       Definition at line 141 of file zgtcon.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2							  Tue Sep 25 2012						       zgtcon.f(3)

Check Out this Related Man Page

ZGTCON(l)								 )								 ZGTCON(l)

NAME

       ZGTCON - estimate the reciprocal of the condition number of a complex tridiagonal matrix A using the LU factorization as computed by ZGTTRF

SYNOPSIS

       SUBROUTINE ZGTCON( NORM, N, DL, D, DU, DU2, IPIV, ANORM, RCOND, WORK, INFO )

	   CHARACTER	  NORM

	   INTEGER	  INFO, N

	   DOUBLE	  PRECISION ANORM, RCOND

	   INTEGER	  IPIV( * )

	   COMPLEX*16	  D( * ), DL( * ), DU( * ), DU2( * ), WORK( * )

PURPOSE

       ZGTCON estimates the reciprocal of the condition number of a complex tridiagonal matrix A using the LU factorization as computed by ZGTTRF.
       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

       NORM    (input) CHARACTER*1
	       Specifies whether the 1-norm condition number or the infinity-norm condition number is required:
	       = '1' or 'O':  1-norm;
	       = 'I':	      Infinity-norm.

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

       DL      (input) COMPLEX*16 array, dimension (N-1)
	       The (n-1) multipliers that define the matrix L from the LU factorization of A as computed by ZGTTRF.

       D       (input) COMPLEX*16 array, dimension (N)
	       The n diagonal elements of the upper triangular matrix U from the LU factorization of A.

       DU      (input) COMPLEX*16 array, dimension (N-1)
	       The (n-1) elements of the first superdiagonal of U.

       DU2     (input) COMPLEX*16 array, dimension (N-2)
	       The (n-2) elements of the second superdiagonal of U.

       IPIV    (input) INTEGER array, dimension (N)
	       The pivot indices; for 1 <= i <= n, row i of the matrix was interchanged with row IPIV(i).  IPIV(i) will always be either i or i+1;
	       IPIV(i) = i indicates a row interchange was not required.

       ANORM   (input) DOUBLE PRECISION
	       If NORM = '1' or 'O', the 1-norm of the original matrix A.  If NORM = 'I', the infinity-norm of the original 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)

       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 							 ZGTCON(l)

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zgtcon.f(3) [centos man page]

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