naginterfaces.library.matop.dtrttp

naginterfaces.library.matop.dtrttp(uplo, a)[source]

dtrttp copies a real triangular matrix, stored in a full format array, to a standard packed format array.

For full information please refer to the NAG Library document for f01va

https://www.nag.com/numeric/nl/nagdoc_28.4/flhtml/f01/f01vaf.html

Parameters
uplostr, length 1

Specifies whether is upper or lower triangular.

is upper triangular.

is lower triangular.

afloat, array-like, shape

The triangular matrix .

Returns
apfloat, ndarray, shape

The triangular matrix , packed by columns.

Raises
NagValueError
(errno )

On entry, error in parameter .

Constraint: or .

(errno )

On entry, error in parameter .

Constraint: .

Notes

dtrttp packs a real triangular matrix , stored conventionally in a full format array, into an array of length . The matrix is packed by columns. This function is intended for possible use in conjunction with functions from submodule blas, submodule blast, submodule lapacklin and submodule lapackeig where some functions use triangular matrices stored in the packed form. Packed storage format is described in the F07 Introduction.