dlanhs.f man page

dlanhs.f —

Synopsis

Functions/Subroutines

DOUBLE PRECISION function dlanhs (NORM, N, A, LDA, WORK)
DLANHS 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

DOUBLE PRECISION function dlanhs (characterNORM, integerN, double precision, dimension( lda, * )A, integerLDA, double precision, dimension( * )WORK)

DLANHS 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:

DLANHS  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:

DLANHS

   DLANHS = ( 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 DLANHS as described
above.

N

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

A

A is DOUBLE PRECISION 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 DOUBLE PRECISION 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 dlanhs.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

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

Sat Nov 16 2013 Version 3.4.2 LAPACK