clanhe(3)

NAME

CLANHE - return the value of the one norm, or the Frobe

nius norm, or the infinity norm, or the element of largest abso

lute value of a complex hermitian matrix A

SYNOPSIS

REAL FUNCTION CLANHE( NORM, UPLO, N, A, LDA, WORK )
    CHARACTER NORM, UPLO
    INTEGER   LDA, N
    REAL      WORK( * )
    COMPLEX   A( LDA, * )

PURPOSE

CLANHE returns the value of the one norm, or the Frobenius

norm, or the infinity norm, or the element of largest absolute

value of a complex hermitian matrix A.

DESCRIPTION

CLANHE returns the value

CLANHE = ( max(abs(A(i,j))), NORM = 'M' or 'm'

(
( norm1(A), NORM = '1', 'O' or 'o'
(
( normI(A), NORM = 'I' or 'i'
(
( normF(A), NORM = 'F', 'f', 'E' or

'e'

where norm1 denotes the one norm of a matrix (maximum

column sum), normI denotes the infinity norm of a matrix

(maximum row sum) and normF denotes the Frobenius norm of a ma

trix (square root of sum of squares). Note that

max(abs(A(i,j))) is not a matrix norm.

ARGUMENTS

NORM (input) CHARACTER*1

Specifies the value to be returned in CLANHE as

described above.

UPLO (input) CHARACTER*1

Specifies whether the upper or lower triangular

part of the hermitian matrix A is to be referenced. = 'U': Up

per triangular part of A is referenced
= 'L': Lower triangular part of A is referenced

N (input) INTEGER

The order of the matrix A. N >= 0. When N = 0,

CLANHE is set to zero.

A (input) COMPLEX array, dimension (LDA,N)

The hermitian matrix A. If UPLO = 'U', the lead

ing n by n upper triangular part of A contains the upper triangu

lar 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 ref

erenced. Note that the imaginary parts of the diagonal elements

need not be set and are assumed to be zero.

LDA (input) INTEGER

The leading dimension of the array A. LDA >=

max(N,1).

WORK (workspace) REAL array, dimension (LWORK),

where LWORK >= N when NORM = 'I' or '1' or 'O';

otherwise, WORK is not referenced.

LAPACK version 3.0 15 June 2000

CLANHE(3)