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CLANHS(1) LAPACK auxiliary routine (version 3.2) CLANHS(1)

NAME

CLANHS - returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a Hessenberg matrix A

SYNOPSIS

CLANHS( NORM, N, A, LDA, WORK )

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

PURPOSE

CLANHS returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a Hessenberg matrix A.

DESCRIPTION

CLANHS returns the value
CLANHS = ( 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 matrix (square root of sum of squares). Note that max(abs(A(i,j))) is not a consistent matrix norm.

ARGUMENTS

Specifies the value to be returned in CLANHS as described above.
The order of the matrix A. N >= 0. When N = 0, CLANHS is set to zero.
The n by n upper Hessenberg matrix A; the part of A below the first sub-diagonal is not referenced.
The leading dimension of the array A. LDA >= max(N,1).
where LWORK >= N when NORM = 'I'; otherwise, WORK is not referenced.
November 2008 LAPACK auxiliary routine (version 3.2)