subdivisor_uv_binary.hpp

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/*****************************************************************************
 * M a t h e m a g i x
 *****************************************************************************
 * cell for univariate bernstein equation
 * 2008-05-16
 *****************************************************************************
 *               Copyright (C) 2010 INRIA Sophia-Antipolis
 *****************************************************************************
 * Comments :
 ****************************************************************************/
# ifndef realroot_subdivisor_uv_binary_hpp
# define realroot_subdivisor_uv_binary_hpp

# include <realroot/sign_variation.hpp>
# include <realroot/polynomial_bernstein.hpp>
# include <realroot/subdivisor.hpp>

//====================================================================
namespace mmx {

struct uv_binary_approx {
  
  static double m_eps;

  template<class Cell, class Stack>
  static void subdivide(Cell* cl, Stack* stack);

  template<class Cell>
  static bool reduce(Cell* cl);

  template<class Cell>
  static bool regular(Cell* cl);

} ;

double uv_binary_approx::m_eps=1e-6;

template<class Cell, class Stack> void 
uv_binary_approx::subdivide(Cell* cl, Stack* st) {

  Cell* left  = new Cell(*cl);
  Cell* right = new Cell(*cl);

  unsigned v=0; 
  //  typename Cell::Scalar s=cl->domain().upper()-cl->domain().lower(),s0;

  typename Cell::Scalar m=(cl->domain().upper()+cl->domain().lower())/2;

  tensor::split(left->equation(), right->equation(), v);
  left->domain().upper()=m;
  right->domain().lower()=m;

  //  std::cout<<"==> "<<left->equation(0)<< " "<<left->domain(0)<<std::endl;
  //  std::cout<<"==> "<<right->equation(0)<< " "<<right->domain(0)<<std::endl;
  //  std::cout<<std::endl;

  st->push(left); 
  st->push(right);
};

template<class Cell> bool
uv_binary_approx::reduce(Cell* cl) {  
  if(cl->size() < m_eps) return false;
  if(!has_sign_variation(cl->equation())) return false;
  return true; 
}

template<class Cell> bool
uv_binary_approx::regular(Cell* cl) { 
  if(!has_sign_variation(cl->equation())) return false;
  return true;
}

//--------------------------------------------------------------------
struct uv_binary_isolate: uv_binary_approx {
  
  template<class Cell>
  static bool reduce(Cell* cl);

} ;

template<class Cell> bool
uv_binary_isolate::reduce(Cell* cl) {  
  if(cl->size() < m_eps) return false;
  if(!has_sign_variation(cl->equation())) return false;
  
  return true; 
}

//====================================================================
} // namespace mmx
//====================================================================
# undef TMPL
# undef SELF
# endif