# naginterfaces.library.blas.dlansb¶

naginterfaces.library.blas.dlansb(norm, uplo, k, ab)[source]

dlansb returns the value of the -norm, the -norm, the Frobenius norm, or the maximum absolute value of the elements of a real symmetric band matrix.

For full information please refer to the NAG Library document for f06re

https://www.nag.com/numeric/nl/nagdoc_28.7/flhtml/f06/f06ref.html

Parameters
normstr, length 1

Specifies the value to be returned.

or

The -norm.

The -norm (= the -norm for a symmetric matrix).

or

The Frobenius (or Euclidean) norm.

The value (not a norm).

uplostr, length 1

Specifies whether the upper or lower triangular part of is stored.

The upper triangular part of is stored.

The lower triangular part of is stored.

kint

, the number of subdiagonals or superdiagonals of the matrix .

abfloat, array-like, shape

The symmetric band matrix .

Returns
nrmfloat

The value of the -norm, the -norm, the Frobenius norm, or the maximum absolute value of the elements of the real symmetric band matrix.

Raises
NagValueError
(errno )

On entry, error in parameter .

Constraint: , , , , or .

(errno )

On entry, error in parameter .

Constraint: or .

(errno )

On entry, error in parameter .

Constraint: .

(errno )

On entry, error in parameter .

Constraint: .

Notes

No equivalent traditional C interface for this routine exists in the NAG Library.