# naginterfaces.library.blas.dlanst¶

naginterfaces.library.blas.dlanst(norm, d, e)[source]

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

For full information please refer to the NAG Library document for f06rp

https://www.nag.com/numeric/nl/nagdoc_28.7/flhtml/f06/f06rpf.html

Parameters
normstr, length 1

Specifies the value to be returned.

or

The -norm.

The -norm.

or

The Frobenius (or Euclidean) norm.

The value (not a norm).

dfloat, array-like, shape

The diagonal elements of the tridiagonal matrix .

efloat, array-like, shape

The () subdiagonal or superdiagonal elements of the tridiagonal 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 tridiagonal matrix .

Raises
NagValueError
(errno )

On entry, error in parameter .

Constraint: , , , , or .

(errno )

On entry, error in parameter .

Constraint: .

Notes

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