##### gbcon

###### Prototype

There is one prototype of `gbcon` available, please see below.

    gbcon( const char norm, const MatrixAB& ab, const VectorIPIV& ipiv,
            const Scalar >, Scalar > );

###### Description

`gbcon` (short for $FRIENDLY_NAME) provides a C++ interface to LAPACK routines SGBCON, DGBCON, CGBCON, and ZGBCON. `gbcon` estimates the reciprocal of the condition number of a complex general band matrix A, in either the 1-norm or the infinity-norm, using the LU factorization computed by ZGBTRF.

An estimate is obtained for norm(inv(A)), and the reciprocal of the condition number is computed as RCOND = 1 / ( norm(A) * norm(inv(A)) ).

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

Table 1.238. Dispatching of gbcon

Value type of MatrixAB | LAPACK routine
--- | ---
`float` | SGBCON
`double` | DGBCON
`complex<float>` | CGBCON
`complex<double>` | ZGBCON

###### Definition

Defined in header `boost/numeric/bindings/lapack/computational/gbcon.hpp`.

###### Parameters or Requirements on Types

Parameters

MatrixA

  The definition of term 1

MatrixB

  The definition of term 2

MatrixC

  The definition of term 3.

  Definitions may contain paragraphs.

###### Complexity

###### Example

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

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

this will output

    [5] 0 1 2 3 4 5

###### Notes

###### See Also

- Originating Fortran source files sgbcon.f, dgbcon.f, cgbcon.f, and zgbcon.f at Netlib.