Content

BLAS Level 2: mv

mv (defined in namespace flens::blas) computes matrix vector products.

Depending on the involved matrix type specialized variants are defined.

General Matrix

For a general matrix \(A\) and dense vectors \(x\), \(y\) the function computes matrix-vector products of the form \(y \leftarrow \beta y + \alpha \, \text{op}(A) \, x\) where \(\text{op}(X)\) denotes \(X\), \(X^T\) or \(X^H\).

GeMatrix

trans

(input)
Specifiy the operation, i.e.

NoTrans

\(y \leftarrow \beta y + \alpha A x\)

Trans

\(y \leftarrow \beta y + \alpha A^T x\)

ConjTrans

\(y \leftarrow \beta y + \alpha A^H x\)

alpha

(input) real or complex scalar value
Scaling factor \(\alpha\).

A

(input) real or complex valued GeMatrix
Matrix \(A\).

x

(input) real or complex valued DenseVector
Vector \(x\).

beta

(input)
Scaling factor \(\beta\). If \(\beta\) is zero and \(y\) has length zero then \(y\) gets resized.

y

(input/output) real or complex valued DenseVector
Vector \(y\).

GeCCSMatrix

trans

(input)
Specifiy the operation, i.e.

NoTrans

\(y \leftarrow \beta y + \alpha A x\)

Trans

\(y \leftarrow \beta y + \alpha A^T x\)

ConjTrans

\(y \leftarrow \beta y + \alpha A^H x\)

alpha

(input) real or complex scalar value
Scaling factor \(\alpha\).

A

(input) real or complex valued GeCCSMatrix
Matrix \(A\).

x

(input) real or complex valued DenseVector
Vector \(x\).

beta

(input)
Scaling factor \(\beta\). If \(\beta\) is zero and \(y\) has length zero then \(y\) gets resized.

y

(input/output) real or complex valued DenseVector
Vector \(y\).

GeCRSMatrix

trans

(input)
Specifiy the operation, i.e.

NoTrans

\(y \leftarrow \beta y + \alpha A x\)

Trans

\(y \leftarrow \beta y + \alpha A^T x\)

ConjTrans

\(y \leftarrow \beta y + \alpha A^H x\)

alpha

(input) real or complex scalar value
Scaling factor \(\alpha\).

A

(input) real or complex valued GeCRSMatrix
Matrix \(A\).

x

(input) real or complex valued DenseVector
Vector \(x\).

beta

(input)
Scaling factor \(\beta\). If \(\beta\) is zero and \(y\) has length zero then \(y\) gets resized.

y

(input/output) real or complex valued DenseVector
Vector \(y\).

Triangular Matrix

For a triangular matrix \(A\) and a dense vectors \(x\) the function computes matrix-vector products of the form \(x \leftarrow \text{op}(A) \, x\) where \(\text{op}(X)\) denotes \(X\), \(X^T\) or \(X^H\).

trans

(input)
Specifiy the operation, i.e.

NoTrans

\(x \leftarrow A x\)

Trans

\(x \leftarrow A^T x\)

ConjTrans

\(x \leftarrow A^H x\)

A

(input) real or complex valued TrMatrix
Triangular Matrix \(A\).

x

(input/output) real or complex valued DenseVector
Vector \(x\).

Symmetric Matrix

For a symmetric matrix \(A\) and dense vectors \(x, y\) the function computes matrix-vector products of the form \(y \leftarrow \beta y + \alpha \, A \, x\).

SyMatrix

alpha

(input) real or complex scalar value
Scaling factor \(\alpha\).

A

(input) real or complex valued SyMatrix
Symmetric matrix \(A\).

x

(input) real or complex valued DenseVector
Vector \(x\).

beta

(input)
Scaling factor \(\beta\). If \(\beta\) is zero and \(y\) has length zero then \(y\) gets resized.

y

(input/output) real or complex valued DenseVector
Vector \(y\).

SyCCSMatrix

alpha

(input) real or complex scalar value
Scaling factor \(\alpha\).

A

(input) real or complex valued SyCCSMatrix
Symmetric matrix \(A\).

x

(input) real or complex valued DenseVector
Vector \(x\).

beta

(input)
Scaling factor \(\beta\). If \(\beta\) is zero and \(y\) has length zero then \(y\) gets resized.

y

(input/output) real or complex valued DenseVector
Vector \(y\).

SyCRSMatrix

alpha

(input) real or complex scalar value
Scaling factor \(\alpha\).

A

(input) real or complex valued SyCRSMatrix
Symmetric matrix \(A\).

x

(input) real or complex valued DenseVector
Vector \(x\).

beta

(input)
Scaling factor \(\beta\). If \(\beta\) is zero and \(y\) has length zero then \(y\) gets resized.

y

(input/output) real or complex valued DenseVector
Vector \(y\).

Hermitian Matrix

For a hermitian matrix \(A\) and dense vectors \(x, y\) the function computes matrix-vector products of the form \(y \leftarrow \beta y + \alpha \, A \, x\).

HeMatrix

alpha

(input) real or complex scalar value
Scaling factor \(\alpha\).

A

(input) real or complex valued HeMatrix
Hermitian matrix \(A\).

x

(input) real or complex valued DenseVector
Vector \(x\).

beta

(input)
Scaling factor \(\beta\). If \(\beta\) is zero and \(y\) has length zero then \(y\) gets resized.

y

(input/output) real or complex valued DenseVector
Vector \(y\).

HeCCSMatrix

alpha

(input) real or complex scalar value
Scaling factor \(\alpha\).

A

(input) real or complex valued HeCCSMatrix
Hermitian matrix \(A\).

x

(input) real or complex valued DenseVector
Vector \(x\).

beta

(input)
Scaling factor \(\beta\). If \(\beta\) is zero and \(y\) has length zero then \(y\) gets resized.

y

(input/output) real or complex valued DenseVector
Vector \(y\).

HeCRSMatrix

alpha

(input) real or complex scalar value
Scaling factor \(\alpha\).

A

(input) real or complex valued HeCRSMatrix
Hermitian matrix \(A\).

x

(input) real or complex valued DenseVector
Vector \(x\).

beta

(input)
Scaling factor \(\beta\). If \(\beta\) is zero and \(y\) has length zero then \(y\) gets resized.

y

(input/output) real or complex valued DenseVector
Vector \(y\).