# naginterfaces.library.blas.ztbsv¶

naginterfaces.library.blas.ztbsv(uplo, trans, diag, k, a, x)[source]

ztbsv solves a complex triangular banded system of equations with a single right-hand side.

For full information please refer to the NAG Library document for f06sk

https://www.nag.com/numeric/nl/nagdoc_28.7/flhtml/f06/f06skf.html

Parameters
uplostr, length 1

Specifies whether is upper or lower triangular.

is upper triangular.

is lower triangular.

transstr, length 1

Specifies the operation to be performed.

.

.

.

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.

kint

, the number of subdiagonals or superdiagonals of the matrix .

acomplex, array-like, shape

The triangular band matrix

xcomplex, array-like, shape

The vector .

Returns
xcomplex, ndarray, shape

The updated vector .

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: .

(errno )

On entry, error in parameter .

Constraint: .

Notes

In the NAG Library the traditional C interface for this routine uses a different algorithmic base. Please contact NAG if you have any questions about compatibility.

ztbsv performs one of the matrix-vector operations

where is an complex triangular band matrix with subdiagonals or superdiagonals, and is an -element complex vector. denotes or equivalently ; denotes or equivalently .

No test for singularity or near-singularity of is included in this function. Such tests must be performed before calling this function.