CLANHS(3F)							    CLANHS(3F)

NAME    [Toc]    [Back]

     CLANHS - return 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

SYNOPSIS    [Toc]    [Back]

     REAL FUNCTION CLANHS( NORM, N, A, LDA, WORK )

	 CHARACTER NORM

	 INTEGER   LDA,	N

	 REAL	   WORK( * )

	 COMPLEX   A( LDA, * )

PURPOSE    [Toc]    [Back]

     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.

DESCRIPTION    [Toc]    [Back]

     CLANHS returns the	value

	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  matrix norm.

ARGUMENTS    [Toc]    [Back]

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

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

     A	     (input) 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.





									Page 1






CLANHS(3F)							    CLANHS(3F)



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

     WORK    (workspace) REAL array, dimension (LWORK),
	     where LWORK >= N when NORM	= 'I'; otherwise, WORK is not
	     referenced.
CLANHS(3F)							    CLANHS(3F)

NAME    [Toc]    [Back]

     CLANHS - return 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

SYNOPSIS    [Toc]    [Back]

     REAL FUNCTION CLANHS( NORM, N, A, LDA, WORK )

	 CHARACTER NORM

	 INTEGER   LDA,	N

	 REAL	   WORK( * )

	 COMPLEX   A( LDA, * )

PURPOSE    [Toc]    [Back]

     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.

DESCRIPTION    [Toc]    [Back]

     CLANHS returns the	value

	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  matrix norm.

ARGUMENTS    [Toc]    [Back]

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

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

     A	     (input) 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.





									Page 1






CLANHS(3F)							    CLANHS(3F)



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

     WORK    (workspace) REAL array, dimension (LWORK),
	     where LWORK >= N when NORM	= 'I'; otherwise, WORK is not
	     referenced.


									PPPPaaaaggggeeee 2222