Prototype

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

stein( const int_t n, const VectorD& d, const VectorE& e,
        const int_t m, const VectorW& w,
        const VectorIBLOCK& iblock, const VectorISPLIT& isplit, MatrixZ& z,
        VectorIFAIL& ifail );

Description

stein (short for $FRIENDLY_NAME) provides a C++ interface to LAPACK routines SSTEIN, DSTEIN, CSTEIN, and ZSTEIN. stein computes the eigenvectors of a real symmetric tridiagonal matrix T corresponding to specified eigenvalues, using inverse iteration.

The maximum number of iterations allowed for each eigenvector is specified by an internal parameter MAXITS (currently set to 5).

Although the eigenvectors are real, they are stored in a complex array, which may be passed to ZUNMTR or ZUPMTR for back transformation to the eigenvectors of a complex Hermitian matrix which was reduced to tridiagonal form.

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

Definition

Defined in header boost/numeric/bindings/lapack/computational/stein.hpp.

Parameters or Requirements on Types

Complexity

Example

#include <boost/numeric/bindings/lapack/computational/stein.hpp>
using namespace boost::numeric::bindings;

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

this will output

[5] 0 1 2 3 4 5

Notes

See Also