Prototype

There are two prototypes of trexc available, please see below.

trexc( const char compq, MatrixT& t, MatrixQ& q, int_t& ifst,
        int_t& ilst );

trexc( const char compq, MatrixT& t, MatrixQ& q,
        const int_t ifst, const int_t ilst );

Description

trexc (short for $FRIENDLY_NAME) provides a C++ interface to LAPACK routines STREXC, DTREXC, CTREXC, and ZTREXC. trexc reorders the Schur factorization of a complex matrix A = QT*Q*H, so that the diagonal element of T with row index IFST is moved to row ILST.

The Schur form T is reordered by a unitary similarity transformation Z**H*T*Z, and optionally the matrix Q of Schur vectors is updated by postmultplying it with Z.

The selection of the LAPACK routine is done during compile-time, and is determined by the type of values contained in type MatrixT. The type of values is obtained through the value_type meta-function typename value_type<MatrixT>::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/trexc.hpp.

Parameters or Requirements on Types

Complexity

Example

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

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

this will output

[5] 0 1 2 3 4 5

Notes

See Also