CXML
        	    
LAPACK version 3.0
zlansb(3)

PURPOSE
  ZLANSB - return the value of the one norm, or the Frobenius norm, or the
  infinity norm, or the element of largest absolute value of an n by n
  symmetric band matrix A, with k super-diagonals

SYNTAX
  DOUBLE PRECISION FUNCTION ZLANSB( NORM, UPLO, N, K, AB, LDAB, WORK )

      CHARACTER	   NORM, UPLO

      INTEGER	   K, LDAB, N

      DOUBLE	   PRECISION WORK( * )

      COMPLEX*16   AB( LDAB, * )

DESCRIPTION
  ZLANSB returns the value of the one norm, or the Frobenius norm, or the
  infinity norm, or the element of largest absolute value of an n by n
  symmetric band matrix A, with k super-diagonals.

DESCRIPTION
  ZLANSB returns the value

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

  UPLO	  (input) CHARACTER*1
	  Specifies whether the upper or lower triangular part of the band
	  matrix A is supplied.	 = 'U':	 Upper triangular part is supplied
	  = 'L':  Lower triangular part is supplied

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

  K	  (input) INTEGER
	  The number of super-diagonals or sub-diagonals of the band matrix
	  A.  K >= 0.

  AB	  (input) COMPLEX*16 array, dimension (LDAB,N)
	  The upper or lower triangle of the symmetric band matrix A, stored
	  in the first K+1 rows of AB.	The j-th column of A is stored in the
	  j-th column of the array AB as follows: if UPLO = 'U', AB(k+1+i-
	  j,j) = A(i,j) for max(1,j-k)<=i<=j; if UPLO = 'L', AB(1+i-j,j)   =
	  A(i,j) for j<=i<=min(n,j+k).

  LDAB	  (input) INTEGER
	  The leading dimension of the array AB.  LDAB >= K+1.

  WORK	  (workspace) DOUBLE PRECISION array, dimension (LWORK),
	  where LWORK >= N when NORM = 'I' or '1' or 'O'; otherwise, WORK is
	  not referenced.