##### larf

###### Prototype

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

    larf( const Side side, const VectorV& v, const Scalar >, MatrixC& c );

    larf( const Side side, const VectorV& v, const Scalar tau, MatrixC& c );

###### Description

`larf` (short for $FRIENDLY_NAME) provides a C++ interface to LAPACK routines SLARF, DLARF, CLARF, and ZLARF. `larf` applies a complex elementary reflector H to a complex M-by-N matrix C, from either the left or the right. H is represented in the form

H = I - tau * v * v'

where tau is a complex scalar and v is a complex vector.

If tau = 0, then H is taken to be the unit matrix.

To apply H' (the conjugate transpose of H), supply conjg(tau) instead tau.

The selection of the LAPACK routine is done during compile-time, and is determined by the type of values contained in type `VectorV`. The type of values is obtained through the `value_type` meta-function `typename value_type<VectorV>::type`. The dispatching table below illustrates to which specific routine the code path will be generated.

Table 1.340. Dispatching of larf

Value type of VectorV | LAPACK routine
--- | ---
`float` | SLARF
`double` | DLARF
`complex<float>` | CLARF
`complex<double>` | ZLARF

###### Definition

Defined in header `boost/numeric/bindings/lapack/auxiliary/larf.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/lapack/auxiliary/larf.hpp>
    using namespace boost::numeric::bindings;

    lapack::larf( x, y, z );

this will output

    [5] 0 1 2 3 4 5

###### Notes

###### See Also

- Originating Fortran source files slarf.f, dlarf.f, clarf.f, and zlarf.f at Netlib.