symv

Prototype

There is one prototype of symv available, please see below.

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

Description

symv (short for symmetric matrix-vector operation) provides a C++ interface to BLAS routines SSYMV and DSYMV. symv 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 symmetric matrix.

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 1.64. Dispatching of symv.

Value type of MatrixA	BLAS routine	CBLAS routine	CUBLAS routine
`float`	SSYMV	cblas_ssymv	cublasSsymv
`double`	DSYMV	cblas_dsymv	Unavailable

The original routines SSYMV and DSYMV have ten arguments, whereas symv requires five arguments.

Table 1.65. Deduction of arguments of symv.

Definition

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

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

this will output

[5] 0 1 2 3 4 5