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claqhp.f(3) LAPACK claqhp.f(3)
NAME
claqhp.f -
SYNOPSIS
Functions/Subroutines
subroutine claqhp (UPLO, N, AP, S, SCOND, AMAX, EQUED)
CLAQHP scales a Hermitian matrix stored in packed form.
Function/Subroutine Documentation
subroutine claqhp (characterUPLO, integerN, complex, dimension( * )AP,
real, dimension( * )S, realSCOND, realAMAX, characterEQUED)
CLAQHP scales a Hermitian matrix stored in packed form.
Purpose:
CLAQHP equilibrates a Hermitian matrix A using the scaling factors
in the vector S.
Parameters:
UPLO
UPLO is CHARACTER*1
Specifies whether the upper or lower triangular part of the
Hermitian matrix A is stored.
= 'U': Upper triangular
= 'L': Lower triangular
N
N is INTEGER
The order of the matrix A. N >= 0.
AP
AP is COMPLEX 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 j-th column of A
is stored in the array AP as follows:
if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n.
On exit, the equilibrated matrix: diag(S) * A * diag(S), in
the same storage format as A.
S
S is REAL array, dimension (N)
The scale factors for A.
SCOND
SCOND is REAL
Ratio of the smallest S(i) to the largest S(i).
AMAX
AMAX is REAL
Absolute value of largest matrix entry.
EQUED
EQUED is 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= 'Y': Equilibration was done, i.e., A has been replaced by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).
Internal 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.
Author:
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
September 2012
Definition at line 127 of file claqhp.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Sat Nov 16 2013 claqhp.f(3)