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LAPACK version 3.0
zlangb(3)

PURPOSE
  ZLANGB - 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 band
  matrix A, with kl sub-diagonals and ku super-diagonals

SYNTAX
  DOUBLE PRECISION FUNCTION ZLANGB( NORM, N, KL, KU, AB, LDAB, WORK )

      CHARACTER	   NORM

      INTEGER	   KL, KU, LDAB, N

      DOUBLE	   PRECISION WORK( * )

      COMPLEX*16   AB( LDAB, * )

DESCRIPTION
  ZLANGB 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 band
  matrix A, with kl sub-diagonals and ku super-diagonals.

DESCRIPTION
  ZLANGB returns the value

     ZLANGB = ( 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 ZLANGB as described above.

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

  KL	  (input) INTEGER
	  The number of sub-diagonals of the matrix A.	KL >= 0.

  KU	  (input) INTEGER
	  The number of super-diagonals of the matrix A.  KU >= 0.

  AB	  (input) COMPLEX*16 array, dimension (LDAB,N)
	  The band matrix A, stored in rows 1 to KL+KU+1.  The j-th column of
	  A is stored in the j-th column of the array AB as follows:
	  AB(ku+1+i-j,j) = A(i,j) for max(1,j-ku)<=i<=min(n,j+kl).

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

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