SRC/clangb.f(3)            Library Functions Manual            SRC/clangb.f(3)

NAME
       SRC/clangb.f

SYNOPSIS
   Functions/Subroutines
       real function clangb (norm, n, kl, ku, ab, ldab, work)
           CLANGB returns the value of the 1-norm, Frobenius norm,
           infinity-norm, or the largest absolute value of any element of
           general band matrix.

Function/Subroutine Documentation
   real function clangb (character norm, integer n, integer kl, integer ku,
       complex, dimension( ldab, * ) ab, integer ldab, real, dimension( * )
       work)
       CLANGB returns the value of the 1-norm, Frobenius norm, infinity-norm,
       or the largest absolute value of any element of general band matrix.

       Purpose:


            CLANGB  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.

       Returns
           CLANGB

               CLANGB = ( 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 consistent matrix norm.

       Parameters
           NORM

                     NORM is CHARACTER*1
                     Specifies the value to be returned in CLANGB as described
                     above.

           N

                     N is INTEGER
                     The order of the matrix A.  N >= 0.  When N = 0, CLANGB is
                     set to zero.

           KL

                     KL is INTEGER
                     The number of sub-diagonals of the matrix A.  KL >= 0.

           KU

                     KU is INTEGER
                     The number of super-diagonals of the matrix A.  KU >= 0.

           AB

                     AB is COMPLEX 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

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

           WORK

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

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 123 of file clangb.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0                 SRC/clangb.f(3)