Discontinuous Galerkin Library
#include "dg/algorithm.h"
dg::DLT< real_type > Class Template Reference

Struct holding coefficients for Discrete Legendre Transformation (DLT) related operations. More...

Public Member Functions

 DLT (unsigned n=3)
 Initialize coefficients. More...
 
unsigned n () const
 # of polynomial coefficients More...
 
const std::vector< real_type > & weights () const
 Return Gauss-Legendre weights. More...
 
const std::vector< real_type > & abscissas () const
 Return Gauss-Legendre nodes on the interval [-1,1]. More...
 
const std::vector< real_type > & forward () const
 Return forward DLT trafo matrix. More...
 
const std::vector< real_type > & backward () const
 Return backward DLT trafo matrix. More...
 
const std::vector< real_type > & backwardEQ () const
 Return equidistant backward DLT trafo matrix. More...
 

Detailed Description

template<class real_type>
class dg::DLT< real_type >

Struct holding coefficients for Discrete Legendre Transformation (DLT) related operations.

Template Parameters
real_typevalue type (double or float)

Constructor & Destructor Documentation

◆ DLT()

template<class real_type >
dg::DLT< real_type >::DLT ( unsigned  n = 3)

Initialize coefficients.

The constructor initializes internal data with tabulated values for the given number of polynomial coefficients.

Parameters
n# of polynomial coefficients (0<n<21)

Member Function Documentation

◆ abscissas()

template<class real_type >
const std::vector< real_type > & dg::DLT< real_type >::abscissas ( ) const
inline

Return Gauss-Legendre nodes on the interval [-1,1].

Returns
n nodes

◆ backward()

template<class real_type >
const std::vector< real_type > & dg::DLT< real_type >::backward ( ) const
inline

Return backward DLT trafo matrix.

accesss elements in C-fashion: \( F_{ij} =\) backward()[i*n+j]

Returns
n*n backward transformation coefficients

◆ backwardEQ()

template<class real_type >
const std::vector< real_type > & dg::DLT< real_type >::backwardEQ ( ) const
inline

Return equidistant backward DLT trafo matrix.

For vizualisation purposes it is useful to have the values of the DLT - expansion on an equidistant grid. accesss elements in C-fashion: \( F_{ij} = \) backwardEQ()[i*n+j]

Returns
n*n equidistant backward transformation coefficients

◆ forward()

template<class real_type >
const std::vector< real_type > & dg::DLT< real_type >::forward ( ) const
inline

Return forward DLT trafo matrix.

accesss elements in C-fashion: \( F_{ij} = \) forward()[i*n+j]

Returns
n*n forward transformation coefficients

◆ n()

template<class real_type >
unsigned dg::DLT< real_type >::n ( ) const
inline

# of polynomial coefficients

◆ weights()

template<class real_type >
const std::vector< real_type > & dg::DLT< real_type >::weights ( ) const
inline

Return Gauss-Legendre weights.

Returns
n weights

The documentation for this class was generated from the following file: