##### 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

###### Notes

###### See Also

- Originating Fortran source files ssbmv.f, dsbmv.f, chbmv.f, and zhbmv.f at Netlib.