Home Man
Search
Today's Posts
Register

Linux & Unix Commands - Search Man Pages

RedHat 9 (Linux i386) - man page for zlaqhb (redhat section l)

ZLAQHB(l)					)					ZLAQHB(l)

NAME
       ZLAQHB - equilibrate a symmetric band matrix A using the scaling factors in the vector S

SYNOPSIS
       SUBROUTINE ZLAQHB( UPLO, N, KD, AB, LDAB, S, SCOND, AMAX, EQUED )

	   CHARACTER	  EQUED, UPLO

	   INTEGER	  KD, LDAB, N

	   DOUBLE	  PRECISION AMAX, SCOND

	   DOUBLE	  PRECISION S( * )

	   COMPLEX*16	  AB( LDAB, * )

PURPOSE
       ZLAQHB equilibrates a symmetric band matrix A using the scaling factors in the vector S.

ARGUMENTS
       UPLO    (input) CHARACTER*1
	       Specifies  whether the upper or lower triangular part of the symmetric matrix A is
	       stored.	= 'U':	Upper triangular
	       = 'L':  Lower triangular

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

       KD      (input) INTEGER
	       The number of super-diagonals of the matrix A if UPLO = 'U', or the number of sub-
	       diagonals if UPLO = 'L'.  KD >= 0.

       AB      (input/output) COMPLEX*16 array, dimension (LDAB,N)
	       On  entry,  the	upper or lower triangle of the symmetric band matrix A, stored in
	       the first KD+1 rows of the array.  The j-th column of A is stored in the j-th col-
	       umn  of	the  array  AB	as  follows:  if  UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for
	       max(1,j-kd)<=i<=j; if UPLO = 'L', AB(1+i-j,j)	= A(i,j) for j<=i<=min(n,j+kd).

	       On exit, if INFO = 0, the triangular factor U or L from the Cholesky factorization
	       A = U'*U or A = L*L' of the band matrix A, in the same storage format as A.

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

       S       (output) DOUBLE PRECISION array, dimension (N)
	       The scale factors for A.

       SCOND   (input) DOUBLE PRECISION
	       Ratio of the smallest S(i) to the largest S(i).

       AMAX    (input) DOUBLE PRECISION
	       Absolute value of largest matrix entry.

       EQUED   (output) CHARACTER*1
	       Specifies whether or not equilibration was done.  = 'N':  No equilibration.
	       =  'Y':	 Equilibration	was  done,  i.e.,  A  has  been replaced by diag(S) * A *
	       diag(S).

PARAMETERS
       THRESH is a threshold value used to decide if scaling should be done based on the ratio of
       the scaling factors.  If SCOND < THRESH, scaling is done.

       LARGE and SMALL are threshold values used to decide if scaling should be done based on the
       absolute size of the largest matrix element.  If AMAX > LARGE or AMAX < SMALL, scaling  is
       done.

LAPACK version 3.0			   15 June 2000 				ZLAQHB(l)


All times are GMT -4. The time now is 05:28 AM.

Unix & Linux Forums Content Copyrightę1993-2018. All Rights Reserved.
UNIX.COM Login
Username:
Password:  
Show Password