# naginterfaces.library.blas.zsyr2k¶

naginterfaces.library.blas.zsyr2k(uplo, trans, k, alpha, a, b, beta, c)[source]

zsyr2k performs one of the symmetric rank- update operations

where and are complex matrices, is an complex symmetric matrix, and and are complex scalars.

For full information please refer to the NAG Library document for f06zw

https://www.nag.com/numeric/nl/nagdoc_28.7/flhtml/f06/f06zwf.html

Parameters
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.

transstr, length 1

Specifies the operation to be performed.

.

.

kint

, the number of columns of and if , or the number of rows of and if .

alphacomplex

The scalar .

acomplex, array-like, shape

Note: the required extent for this argument in dimension 1 is determined as follows: if : ; if : ; otherwise: .

Note: the required extent for this argument in dimension 2 is determined as follows: if : ; if : ; otherwise: .

The matrix ; is if , or if .

bcomplex, array-like, shape

Note: the required extent for this argument in dimension 1 is determined as follows: if : ; if : ; otherwise: .

Note: the required extent for this argument in dimension 2 is determined as follows: if : ; if : ; otherwise: .

The matrix ; is if , or if .

betacomplex

The scalar .

ccomplex, array-like, shape

The symmetric matrix .

Returns
ccomplex, ndarray, shape

The updated 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