##### largv

###### Prototype

There is one prototype of `largv` available, please see below.

    largv( const int_t n, VectorX& x, VectorY& y, VectorC& c );

###### Description

`largv` (short for $FRIENDLY_NAME) provides a C++ interface to LAPACK routines SLARGV, DLARGV, CLARGV, and ZLARGV. `largv` generates a vector of complex plane rotations with real cosines, determined by elements of the complex vectors x and y. For i = 1,2,...,n

( c(i) s(i) ) ( x(i) ) = ( r(i) ) ( -conjg(s(i)) c(i) ) ( y(i) ) = ( 0 )

where c(i)*2 + ABS(s(i))*2 = 1

The following conventions are used (these are the same as in ZLARTG, but differ from the BLAS1 routine ZROTG): If y(i)=0, then c(i)=1 and s(i)=0. If x(i)=0, then c(i)=0 and s(i) is chosen so that r(i) is real.

The selection of the LAPACK 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`. The dispatching table below illustrates to which specific routine the code path will be generated.

Table 1.366. Dispatching of largv

Value type of VectorX | LAPACK routine
--- | ---
`float` | SLARGV
`double` | DLARGV
`complex<float>` | CLARGV
`complex<double>` | ZLARGV

###### Definition

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

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

this will output

    [5] 0 1 2 3 4 5

###### Notes

###### See Also

- Originating Fortran source files slargv.f, dlargv.f, clargv.f, and zlargv.f at Netlib.