Prototype

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

latrs( const char uplo, const char normin, const MatrixA& a, VectorX& x,
        Scalar >, VectorCNORM& cnorm );

Description

latrs (short for $FRIENDLY_NAME) provides a C++ interface to LAPACK routines SLATRS, DLATRS, CLATRS, and ZLATRS. latrs solves one of the triangular systems

A * x = sb, A*T * x = sb, or A*H * x = s*b,

with scaling to prevent overflow. Here A is an upper or lower triangular matrix, A*T denotes the transpose of A, A*H denotes the conjugate transpose of A, x and b are n-element vectors, and s is a scaling factor, usually less than or equal to 1, chosen so that the components of x will be less than the overflow threshold. If the unscaled problem will not cause overflow, the Level 2 BLAS routine ZTRSV is called. If the matrix A is singular (A(j,j) = 0 for some j), then s is set to 0 and a non-trivial solution to A*x = 0 is returned.

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/auxiliary/latrs.hpp.

Parameters or Requirements on Types

Complexity

Example

#include <boost/numeric/bindings/lapack/auxiliary/latrs.hpp>
using namespace boost::numeric::bindings;

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

this will output

[5] 0 1 2 3 4 5

Notes

See Also