claqhe.f - Man Page

SRC/claqhe.f

Synopsis

Functions/Subroutines

subroutine claqhe (uplo, n, a, lda, s, scond, amax, equed)
CLAQHE scales a Hermitian matrix.

Function/Subroutine Documentation

subroutine claqhe (character uplo, integer n, complex, dimension( lda, * ) a, integer lda, real, dimension( * ) s, real scond, real amax, character equed)

CLAQHE scales a Hermitian matrix.

Purpose:

``` CLAQHE 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.```

A

```          A is COMPLEX array, dimension (LDA,N)
On entry, the Hermitian 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

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

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= 'Y':  Equilibration was done, i.e., A has been replaced by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

NAG Ltd.

Definition at line 133 of file claqhe.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

The man page claqhe(3) is an alias of claqhe.f(3).

Tue Nov 28 2023 12:08:41 Version 3.12.0 LAPACK