CLANGT(3F)							    CLANGT(3F)

NAME    [Toc]    [Back]

     CLANGT - return the value of the one norm,	or the Frobenius norm, or the
     infinity norm, or the element of largest absolute value of	a complex
     tridiagonal matrix	A

SYNOPSIS    [Toc]    [Back]

     REAL FUNCTION CLANGT( NORM, N, DL,	D, DU )

	 CHARACTER NORM

	 INTEGER   N

	 COMPLEX   D( *	), DL( * ), DU(	* )

PURPOSE    [Toc]    [Back]

     CLANGT  returns the value of the one norm,	 or the	Frobenius norm,	or the
     infinity norm,  or	the  element of	 largest absolute value	 of a complex
     tridiagonal matrix	A.

DESCRIPTION    [Toc]    [Back]

     CLANGT returns the	value

	CLANGT = ( 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 CLANGT as described above.

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

     DL	     (input) COMPLEX array, dimension (N-1)
	     The (n-1) sub-diagonal elements of	A.

     D	     (input) COMPLEX array, dimension (N)
	     The diagonal elements of A.





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CLANGT(3F)							    CLANGT(3F)



     DU	     (input) COMPLEX array, dimension (N-1)
	     The (n-1) super-diagonal elements of A.
CLANGT(3F)							    CLANGT(3F)

NAME    [Toc]    [Back]

     CLANGT - return the value of the one norm,	or the Frobenius norm, or the
     infinity norm, or the element of largest absolute value of	a complex
     tridiagonal matrix	A

SYNOPSIS    [Toc]    [Back]

     REAL FUNCTION CLANGT( NORM, N, DL,	D, DU )

	 CHARACTER NORM

	 INTEGER   N

	 COMPLEX   D( *	), DL( * ), DU(	* )

PURPOSE    [Toc]    [Back]

     CLANGT  returns the value of the one norm,	 or the	Frobenius norm,	or the
     infinity norm,  or	the  element of	 largest absolute value	 of a complex
     tridiagonal matrix	A.

DESCRIPTION    [Toc]    [Back]

     CLANGT returns the	value

	CLANGT = ( 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 CLANGT as described above.

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

     DL	     (input) COMPLEX array, dimension (N-1)
	     The (n-1) sub-diagonal elements of	A.

     D	     (input) COMPLEX array, dimension (N)
	     The diagonal elements of A.





									Page 1






CLANGT(3F)							    CLANGT(3F)



     DU	     (input) COMPLEX array, dimension (N-1)
	     The (n-1) super-diagonal elements of A.


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