slanhs.f (3)  Linux Manuals
NAME
slanhs.f 
SYNOPSIS
Functions/Subroutines
REAL function slanhs (NORM, N, A, LDA, WORK)
SLANHS returns the value of the 1norm, Frobenius norm, infinitynorm, or the largest absolute value of any element of an upper Hessenberg matrix.
Function/Subroutine Documentation
REAL function slanhs (characterNORM, integerN, real, dimension( lda, * )A, integerLDA, real, dimension( * )WORK)
SLANHS returns the value of the 1norm, Frobenius norm, infinitynorm, or the largest absolute value of any element of an upper Hessenberg matrix.
Purpose:

SLANHS 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.
Returns:

SLANHS
SLANHS = ( 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.
Parameters:

NORM
NORM is CHARACTER*1 Specifies the value to be returned in SLANHS as described above.
NN is INTEGER The order of the matrix A. N >= 0. When N = 0, SLANHS is set to zero.
AA is REAL array, dimension (LDA,N) The n by n upper Hessenberg matrix A; the part of A below the first subdiagonal is not referenced.
LDALDA is INTEGER The leading dimension of the array A. LDA >= max(N,1).
WORKWORK is REAL array, dimension (MAX(1,LWORK)), where LWORK >= N when NORM = 'I'; otherwise, WORK is not referenced.
Author:

Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
 September 2012
Definition at line 109 of file slanhs.f.
Author
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