##### labrd

###### Prototype

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

    labrd( MatrixA& a, VectorD& d, VectorE& e, VectorTAUQ& tauq,
            VectorTAUP& taup, MatrixX& x, MatrixY& y );

###### Description

`labrd` (short for $FRIENDLY_NAME) provides a C++ interface to LAPACK routines SLABRD, DLABRD, CLABRD, and ZLABRD. `labrd` reduces the first NB rows and columns of a complex general m by n matrix A to upper or lower real bidiagonal form by a unitary transformation Q' * A * P, and returns the matrices X and Y which are needed to apply the transformation to the unreduced part of A.

If m >= n, A is reduced to upper bidiagonal form; if m < n, to lower bidiagonal form.

This is an auxiliary routine called by ZGEBRD

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

Table 1.361. Dispatching of labrd

Value type of MatrixA | LAPACK routine
--- | ---
`float` | SLABRD
`double` | DLABRD
`complex<float>` | CLABRD
`complex<double>` | ZLABRD

###### Definition

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

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

this will output

    [5] 0 1 2 3 4 5

###### Notes

###### See Also

- Originating Fortran source files slabrd.f, dlabrd.f, clabrd.f, and zlabrd.f at Netlib.