slanhs.f man page

slanhs.f —

Synopsis

Functions/Subroutines

REAL function slanhs (NORM, N, A, LDA, WORK)
SLANHS returns the value of the 1-norm, Frobenius norm, infinity-norm, 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 1-norm, Frobenius norm, infinity-norm, 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.

N

N is INTEGER
The order of the matrix A.  N >= 0.  When N = 0, SLANHS is
set to zero.

A

A is REAL array, dimension (LDA,N)
The n by n upper Hessenberg matrix A; the part of A below the
first sub-diagonal is not referenced.

LDA

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

WORK

WORK 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

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

slanhs(3) is an alias of slanhs.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK