##### hpmv

###### Prototype

There are two prototypes of `hpmv` available, please see below.

    hpmv( const Scalar >, const MatrixAP& ap, const VectorX& x,
            const Scalar >, VectorY& y );

    hpmv( const Scalar alpha, const MatrixAP& ap, const VectorX& x,
            const Scalar beta, VectorY& y );

###### Description

`hpmv` (short for hermitian, packed, matrix-vector operation) provides a C++ interface to BLAS routines SSPMV, DSPMV, CHPMV, and ZHPMV. `hpmv` 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 matrix, supplied in packed form.

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

Table 1.50. Dispatching of hpmv.

Value type of MatrixAP | BLAS routine | CBLAS routine | CUBLAS routine
--- | --- | --- | ---
`float` | SSPMV | cblas_sspmv | cublasSspmv
`double` | DSPMV | cblas_dspmv | Unavailable
`complex<float>` | CHPMV | cblas_chpmv | cublasChpmv
`complex<double>` | ZHPMV | cblas_zhpmv | Unavailable

The original routines SSPMV, DSPMV, CHPMV, and ZHPMV have nine arguments, whereas `hpmv` requires five arguments.

Table 1.51. Deduction of arguments of hpmv.

###### Definition

Defined in header `boost/numeric/bindings/blas/level2/hpmv.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/hpmv.hpp>
    using namespace boost::numeric::bindings;

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

this will output

    [5] 0 1 2 3 4 5

###### Notes

###### See Also

- Originating Fortran source files sspmv.f, dspmv.f, chpmv.f, and zhpmv.f at Netlib.