naginterfaces.library.blas.dlantr

naginterfaces.library.blas.dlantr(norm, uplo, diag, m, a)[source]

dlantr returns the value of the -norm, the -norm, the Frobenius norm, or the maximum absolute value of the elements of a real trapezoidal matrix (triangular if ).

For full information please refer to the NAG Library document for f06rj

https://support.nag.com/numeric/nl/nagdoc_30.2/flhtml/f06/f06rjf.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).

uplostr, length 1

Specifies whether is upper or lower trapezoidal.

is upper trapezoidal.

is lower trapezoidal.

diagstr, length 1

Specifies whether has nonunit or unit diagonal elements.

The diagonal elements are stored explicitly.

The diagonal elements are assumed to be , and are not referenced.

mint

, the number of rows of the matrix .

When , dlantr is set to zero.

afloat, array-like, shape

The trapezoidal matrix .

Returns
nrmfloat

The value of the -norm, the -norm, the Frobenius norm, or the maximum absolute value of the elements of the real trapezoidal matrix (triangular if ).

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: 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.