# clangb.f(3) [debian man page]

```clangb.f(3)							      LAPACK							       clangb.f(3)

NAME
clangb.f -

SYNOPSIS
Functions/Subroutines
REAL function clangb (NORM, N, KL, KU, AB, LDAB, WORK)
CLANGB

Function/Subroutine Documentation
REAL function clangb (characterNORM, integerN, integerKL, integerKU, complex, dimension( ldab, * )AB, integerLDAB, real, dimension( * )WORK)
CLANGB

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

NAG Ltd.

Date:
November 2011

Definition at line 125 of file clangb.f.

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

Version 3.4.1							  Sun May 26 2013						       clangb.f(3)```

## Check Out this Related Man Page

```slangb.f(3)							      LAPACK							       slangb.f(3)

NAME
slangb.f -

SYNOPSIS
Functions/Subroutines
REAL function slangb (NORM, N, KL, KU, AB, LDAB, WORK)
SLANGB

Function/Subroutine Documentation
REAL function slangb (characterNORM, integerN, integerKL, integerKU, real, dimension( ldab, * )AB, integerLDAB, real, dimension( * )WORK)
SLANGB

Purpose:

SLANGB  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:
SLANGB

SLANGB = ( 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 SLANGB as described
above.

N

N is INTEGER
The order of the matrix A.  N >= 0.  When N = 0, SLANGB 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 REAL 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

NAG Ltd.

Date:
November 2011

Definition at line 124 of file slangb.f.

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

Version 3.4.1							  Sun May 26 2013						       slangb.f(3)```
Man Page