redhat man page for dlaqsy

DLAQSY(l)								 )								 DLAQSY(l)

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

SYNOPSIS
       SUBROUTINE DLAQSY( UPLO, N, A, LDA, S, SCOND, AMAX, EQUED )

	   CHARACTER	  EQUED, UPLO

	   INTEGER	  LDA, N

	   DOUBLE	  PRECISION AMAX, SCOND

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

PURPOSE
       DLAQSY equilibrates a symmetric 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.

       A       (input/output) DOUBLE PRECISION array, dimension (LDA,N)
	       On  entry, the symmetric matrix A.  If UPLO = 'U', the leading n by n upper triangular part of A contains the upper triangular part
	       of the matrix A, and the strictly lower triangular part of A is not referenced.	If UPLO = 'L', the leading n by n lower triangular
	       part of A contains the lower triangular part of the matrix A, and the strictly upper triangular part of A is not referenced.

	       On exit, if EQUED = 'Y', the equilibrated matrix: diag(S) * A * diag(S).

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

       S       (input) 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	       = 'Y':  Equilibration was done, i.e., A has been replaced by diag(S) * A * diag(S).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 							 DLAQSY(l)