radauquadrature.h

利用C

// Copyright (C) 2003-2005 Anders Logg.
// Licensed under the GNU LGPL Version 2.1.
//
// First added:  2003-06-03
// Last changed: 2005-12-09

#ifndef __RADAU_QUADRATURE_H
#define __RADAU_QUADRATURE_H

#include "GaussianQuadrature.h"

namespace dolfin
{

  /// Radau (Gauss-Radau) quadrature on the interval [-1,1].
  /// The n quadrature points are given by the zeros of
  ///
  ///     ( Pn-1(x) + Pn(x) ) / (1+x)
  ///
  /// where Pn is the n:th Legendre polynomial.
  ///
  /// The quadrature points are computed using Newton's method, and
  /// the quadrature weights are computed by solving a linear system
  /// determined by the condition that Radau quadrature with n points
  /// should be exact for polynomials of degree 2n-2.

  class RadauQuadrature : public GaussianQuadrature
  {
  public:
    
    RadauQuadrature(unsigned int n);

    void disp() const;
    
  private:

    void computePoints();

  };
  
}

#endif