##### sptrd

###### Prototype

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

    sptrd( MatrixAP& ap, VectorD& d, VectorE& e, VectorTAU& tau );

###### Description

`sptrd` (short for $FRIENDLY_NAME) provides a C++ interface to LAPACK routines SSPTRD and DSPTRD. `sptrd` reduces a real symmetric matrix A stored in packed form to symmetric tridiagonal form T by an orthogonal similarity transformation: Q**T * A * Q = T.

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

Table 1.317. Dispatching of sptrd

Value type of MatrixAP | LAPACK routine
--- | ---
`float` | SSPTRD
`double` | DSPTRD

###### Definition

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

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

this will output

    [5] 0 1 2 3 4 5

###### Notes

###### See Also

- Originating Fortran source files ssptrd.f and dsptrd.f at Netlib.