CLANHB  -  return the value of the one norm, or the Frobe­
       nius norm, or the infinity norm, or the element of largest
       absolute  value of an n by n hermitian band matrix A, with
       k super-diagonals


SYNOPSIS

       REAL FUNCTION CLANHB( NORM, UPLO, N, K, AB, LDAB, WORK )

           CHARACTER NORM, UPLO

           INTEGER   K, LDAB, N

           REAL      WORK( * )

           COMPLEX   AB( LDAB, * )


PURPOSE

       CLANHB 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 hermitian band matrix A,  with
       k super-diagonals.


DESCRIPTION

       CLANHB returns the value

          CLANHB = ( 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   Frobe­
       nius  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  CLANHB  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
               = 'L':  Lower triangular

               The  order  of the matrix A.  N >= 0.  When N = 0,
               CLANHB 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 array, dimension (LDAB,N)
               The  upper or lower triangle of the hermitian 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).  Note
               that  the imaginary parts of the diagonal elements
               need not be set and are assumed to be zero.

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

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


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