clanhs.f man page

clanhs.f —

Synopsis

Functions/Subroutines

real function clanhs (NORM, N, A, LDA, WORK)
CLANHS 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 clanhs (character NORM, integer N, complex, dimension( lda, * ) A, integer LDA, real, dimension( * ) WORK)

CLANHS 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:

 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.
Returns:

CLANHS

    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.
Parameters:

NORM

          NORM is CHARACTER*1
          Specifies the value to be returned in CLANHS as described
          above.

N

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

A

          A is COMPLEX 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:

December 2016

Definition at line 111 of file clanhs.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

The man page clanhs(3) is an alias of clanhs.f(3).

Sat Jun 24 2017 Version 3.7.1 LAPACK