There is one prototype of stegr
available, please see below.
stegr( const char jobz, const char range, const int_t n, VectorD& d, VectorE& e, const Scalar >, const Scalar >, const int_t il, const int_t iu, const Scalar >, int_t& m, VectorW& w, MatrixZ& z, VectorISUPPZ& isuppz );
stegr
(short for $FRIENDLY_NAME)
provides a C++ interface to LAPACK routines SSTEGR, DSTEGR, CSTEGR, and
ZSTEGR. stegr
computes
selected eigenvalues and, optionally, eigenvectors of a real symmetric
tridiagonal matrix T. Any such unreduced matrix has a well defined set
of pairwise different real eigenvalues, the corresponding real eigenvectors
are pairwise orthogonal.
The spectrum may be computed either completely or partially by specifying either an interval (VL,VU] or a range of indices IL:IU for the desired eigenvalues.
stegr
is a compatability
wrapper around the improved ZSTEMR routine. See DSTEMR for further details.
One important change is that the ABSTOL parameter no longer provides any benefit and hence is no longer used.
Note : stegr
and ZSTEMR
work only on machines which follow IEEE-754 floating-point standard in
their handling of infinities and NaNs. Normal execution may create these
exceptiona values and hence may abort due to a floating point exception
in environments which do not conform to the IEEE-754 standard.
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.
Table 1.320. Dispatching of stegr
Value type of VectorD |
LAPACK routine |
---|---|
|
SSTEGR |
|
DSTEGR |
|
CSTEGR |
|
ZSTEGR |
Defined in header boost/numeric/bindings/lapack/computational/stegr.hpp
.
Parameters
The definition of term 1
The definition of term 2
The definition of term 3.
Definitions may contain paragraphs.
#include <boost/numeric/bindings/lapack/computational/stegr.hpp> using namespace boost::numeric::bindings; lapack::stegr( x, y, z );
this will output
[5] 0 1 2 3 4 5