 LAPACK  3.4.2 LAPACK: Linear Algebra PACKage
slanhs.f File Reference

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## 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 ( character NORM, integer N, real, dimension( lda, * ) A, integer LDA, 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:
 [in] NORM ``` NORM is CHARACTER*1 Specifies the value to be returned in SLANHS as described above.``` [in] N ``` N is INTEGER The order of the matrix A. N >= 0. When N = 0, SLANHS is set to zero.``` [in] 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.``` [in] LDA ``` LDA is INTEGER The leading dimension of the array A. LDA >= max(N,1).``` [out] WORK ``` WORK is REAL array, dimension (MAX(1,LWORK)), where LWORK >= N when NORM = 'I'; otherwise, WORK is not referenced.```
Date:
September 2012

Definition at line 109 of file slanhs.f.

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