hbmv

Prototype

There are two prototypes of hbmv available, please see below.

hbmv( const Scalar >, const MatrixA& a, const VectorX& x,
        const Scalar >, VectorY& y );

hbmv( const Scalar alpha, const MatrixA& a, const VectorX& x,
        const Scalar beta, VectorY& y );

Description

hbmv (short for hermitian, banded, matrix-vector operation) provides a C++ interface to BLAS routines SSBMV, DSBMV, CHBMV, and ZHBMV. hbmv performs the matrix-vector operation

y := alpha*A*x + beta*y,

where alpha and beta are scalars, x and y are n element vectors and A is an n by n hermitian band matrix, with k super-diagonals.

The selection of the BLAS routine is done during compile-time, and is determined by the type of values contained in type MatrixA. The type of values is obtained through the value_type meta-function typename value_type<MatrixA>::type. Table X below illustrates to which specific routine this dispatching will take place.

Table 1.42. Dispatching of hbmv.

Value type of MatrixA	BLAS routine	CBLAS routine	CUBLAS routine
`float`	SSBMV	cblas_ssbmv	cublasSsbmv
`double`	DSBMV	cblas_dsbmv	Unavailable
`complex<float>`	CHBMV	cblas_chbmv	cublasChbmv
`complex<double>`	ZHBMV	cblas_zhbmv	Unavailable

The original routines SSBMV, DSBMV, CHBMV, and ZHBMV have eleven arguments, whereas hbmv requires five arguments.

Table 1.43. Deduction of arguments of hbmv.

Definition

Defined in header boost/numeric/bindings/blas/level2/hbmv.hpp.

Parameters or Requirements on Types

Parameters

MatrixA

The definition of term 1

MatrixB

The definition of term 2

MatrixC

The definition of term 3.

Definitions may contain paragraphs.

Complexity

Example

#include <boost/numeric/bindings/blas/level2/hbmv.hpp>
using namespace boost::numeric::bindings;

blas::hbmv( x, y, z );

this will output

[5] 0 1 2 3 4 5