Prototype

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

syevd( const char jobz, MatrixA& a, VectorW& w );

Description

syevd (short for $FRIENDLY_NAME) provides a C++ interface to LAPACK routines SSYEVD and DSYEVD. syevd computes all eigenvalues and, optionally, eigenvectors of a real symmetric matrix A. If eigenvectors are desired, it uses a divide and conquer algorithm.

The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none.

Because of large use of BLAS of level 3, syevd needs N**2 more workspace than DSYEVX.

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

Definition

Defined in header boost/numeric/bindings/lapack/driver/syevd.hpp.

Parameters or Requirements on Types

Complexity

Example

#include <boost/numeric/bindings/lapack/driver/syevd.hpp>
using namespace boost::numeric::bindings;

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

this will output

[5] 0 1 2 3 4 5

Notes

See Also