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lange
Prototype

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

lange( const char norm, const MatrixA& a );

Description

lange (short for $FRIENDLY_NAME) provides a C++ interface to LAPACK routines SLANGE, DLANGE, CLANGE, and ZLANGE. lange returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a complex matrix A.

Description =====

lange returns the value

lange = ( max(abs(A(i,j))), NORM = 'M' or 'm' ( ( norm1(A), NORM = '1', 'O' or 'o' ( ( normI(A), NORM = 'I' or 'i' ( ( normF(A), NORM = 'F', 'f', 'E' or 'e'

where norm1 denotes the one norm of a matrix (maximum column sum), normI denotes the infinity norm of a matrix (maximum row sum) and normF denotes the Frobenius norm of a matrix (square root of sum of squares). Note that max(abs(A(i,j))) is not a consistent matrix norm.

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.

Table 1.350. Dispatching of lange

Value type of MatrixA

LAPACK routine

float

SLANGE

double

DLANGE

complex<float>

CLANGE

complex<double>

ZLANGE


Definition

Defined in header boost/numeric/bindings/lapack/auxiliary/lange.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/auxiliary/lange.hpp>
using namespace boost::numeric::bindings;

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

this will output

[5] 0 1 2 3 4 5

Notes
See Also

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