
ZLAQHP(l) ) ZLAQHP(l)
NAME
ZLAQHP  equilibrate a Hermitian matrix A using the scaling factors in the vector S
SYNOPSIS
SUBROUTINE ZLAQHP( UPLO, N, AP, S, SCOND, AMAX, EQUED )
CHARACTER EQUED, UPLO
INTEGER N
DOUBLE PRECISION AMAX, SCOND
DOUBLE PRECISION S( * )
COMPLEX*16 AP( * )
PURPOSE
ZLAQHP equilibrates a Hermitian 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 Hermitian matrix A is
stored. = 'U': Upper triangular
= 'L': Lower triangular
N (input) INTEGER
The order of the matrix A. N >= 0.
AP (input/output) COMPLEX*16 array, dimension (N*(N+1)/2)
On entry, the upper or lower triangle of the Hermitian matrix A, packed columnwise
in a linear array. The jth column of A is stored in the array AP as follows: if
UPLO = 'U', AP(i + (j1)*j/2) = A(i,j) for 1<=i<=j; if UPLO = 'L', AP(i +
(j1)*(2nj)/2) = A(i,j) for j<=i<=n.
On exit, the equilibrated matrix: diag(S) * A * diag(S), in the same storage for
mat as A.
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= 'Y': Equilibration was done, i.e., A has been replaced by diag(S) * A *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 ZLAQHP(l) 
