Prototype

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

stebz( const char range, const char order, const int_t n,
        const Scalar >, const Scalar >, const int_t il,
        const int_t iu, const Scalar >, const VectorD& d,
        const VectorE& e, int_t& m, int_t& nsplit,
        VectorW& w, VectorIBLOCK& iblock, VectorISPLIT& isplit );

Description

stebz (short for $FRIENDLY_NAME) provides a C++ interface to LAPACK routines SSTEBZ and DSTEBZ. stebz computes the eigenvalues of a symmetric tridiagonal matrix T. The user may ask for all eigenvalues, all eigenvalues in the half-open interval (VL, VU], or the IL-th through IU-th eigenvalues.

To avoid overflow, the matrix must be scaled so that its largest element is no greater than overflow*(1/2) * underflow*(1/4) in absolute value, and for greatest accuracy, it should not be much smaller than that.

See W. Kahan "Accurate Eigenvalues of a Symmetric Tridiagonal Matrix", Report CS41, Computer Science Dept., Stanford University, July 21, 1966.

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/stebz.hpp.

Parameters or Requirements on Types

Complexity

Example

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

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

this will output

[5] 0 1 2 3 4 5

Notes

See Also