u_smooth_cubic_spline1d.hpp

/* smooth_cubic_spline1d.hpp */
/* $Id$ */
#ifndef __u_smooth_cubic_spline1d_hpp
#define __u_smooth_cubic_spline1d_hpp

#include <vector>
#include <mth/u2d_wpoint.hpp>
#include <mth/u2d_box.hpp>
#include <mth/u_curve1d.hpp>

class SmoothCubicSpline1d : public UCurve1d<U2dWPoint>
{
public:
   
  SmoothCubicSpline1d();
  
  SmoothCubicSpline1d(const U2dWPoints &nodes, double alpha);
  
  virtual ~SmoothCubicSpline1d();
  
  
  virtual double operator()(double x) const;
  
  virtual void approximate(const U2dWPoints &nodes, double alpha);
  
  virtual bool ready() const
  {return m_ready;}
  
  
  virtual void addNode(const U2dWPoint& /*node*/, int /*id*/)
  {printf("SmoothCubicSpline1d::addNode: not implemented.\n");}
  
  virtual bool removeNode(size_t /*id*/)
  {printf("SmoothCubicSpline1d::removeNode: not implemented.\n"); return false;}
  
protected:
  
  struct Coeffs
  {double a,b,c,d,x;};
  typedef std::vector<Coeffs> CoeffsAr;
  
  CoeffsAr m_coeffs;
  
  U2dBox m_bound;
  
  bool m_ready;
  
  // spline linear system matricies and vectors elements
  inline double Am(size_t i, size_t j, const U2dWPoints &nodes) const;
  inline double Hm(size_t i, size_t j, const std::vector<double> &delta_vec) const;
  inline double Km(size_t i, size_t j, const U2dWPoints &nodes) const;
  inline double bv(size_t i, const U2dWPoints &nodes) const;
  
  bool calc_coeffs(const U2dWPoints &nodes, 
           double alpha,
           CoeffsAr &coeffs);
  
  inline double get_s(double x) const;
  
private:
};

#endif /* u_smooth_cubic_spline1d.hpp */