CLANHE - return the value of the one norm, or the Frobe
nius norm, or the infinity norm, or the element of largest
absolute 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 Frobe
nius norm of a matrix (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 refer
enced. = 'U': Upper triangular part of A is ref
erenced
= 'L': Lower triangular part of A is referenced
N (input) INTEGER
The order of the matrix A. N >= 0. When N = 0,
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 triangular part of the matrix A, and the
strictly lower triangular part of A is not refer
enced. 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 tri
angular part of A is not referenced. 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.
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