syr

Prototype

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

syr( const Scalar >, const VectorX& x, MatrixA& a );

Description

syr (short for symmetric rank-1 update) provides a C++ interface to BLAS routines SSYR and DSYR. syr performs the symmetric rank 1 operation

A := alpha*x*x' + A,

where alpha is a real scalar, x is an n element vector 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 VectorX. The type of values is obtained through the value_type meta-function typename value_type<VectorX>::type. Table X below illustrates to which specific routine this dispatching will take place.

Table 1.68. Dispatching of syr.

Value type of VectorX	BLAS routine	CBLAS routine	CUBLAS routine
`float`	SSYR	cblas_ssyr	cublasSsyr
`double`	DSYR	cblas_dsyr	cublasDsyr

The original routines SSYR and DSYR have seven arguments, whereas syr requires three arguments.

Table 1.69. Deduction of arguments of syr.

Definition

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

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

this will output

[5] 0 1 2 3 4 5

syr