Exemple #1
0
void save_bes_cwi_impl(const equation_system& system, std::ostream& stream)
{
  if (system.initial_state() == system.equations().front().variable())
  {
    bes::bes2cwi(system.equations().begin(), system.equations().end(), stream);
  }
  else
  {
    mCRL2log(log::warning) << "The initial state " << system.initial_state() << " and the left hand "
                              "side of the first equation " << system.equations().begin()->variable()
                           << " do not correspond." << std::endl;

    std::vector<typename equation_system::equation_type> equations(system.equations().begin(), system.equations().end());
    if (is_boolean_variable(system.initial_state()) && swap_equations(equations, system.initial_state()))
    {
      mCRL2log(log::warning) << "Fixed by swapping equations for " << equations[0].variable()
                             << " and " << system.initial_state() << std::endl;
    }
    else
    {
      add_fresh_equation(equations, system.initial_state());
      mCRL2log(log::warning) << "Fixed by prepending a new equation " << equations.front() << "."
                             << std::endl;
    }
    bes2cwi(equations.begin(), equations.end(), stream);
  }
}
Exemple #2
0
// Generate the rational approximation x^(pnum/pden)
void AlgRemez::generateApprox()
{
  char *fname = "generateApprox()";

  Float time = -dclock();
  iter = 0;
  spread = 1.0e37;

  if (approx_type == RATIONAL_APPROX_ZERO_POLE) {
    n--;
    neq--;
  }

  initialGuess();
  stpini(step);

  while (spread > tolerance) { //iterate until convergance

    if (iter++%100==0) 
      VRB.Result(cname,fname,"Iteration %d, spread %e delta %e\n", iter-1,(Float)spread,(Float)delta);
    equations();
    if (delta < tolerance)
      ERR.General(cname, fname,"Delta too small, try increasing precision\n");

    search(step);

  }

  int sign;
  Float error = (Float)getErr(mm[0],&sign);
  VRB.Result(cname,fname,"Converged at %d iterations, error = %e\n",
	     iter,error);

  //!< Once the approximation has been generated, calculate the roots
  if(!root()) ERR.General(cname,fname,"Root finding failed\n");
  
  if (approx_type == RATIONAL_APPROX_ZERO_POLE) {
    roots[n] = (bigfloat)0.0;
    n++;
    neq++;
  }

  //!< Now find the partial fraction expansions
  if (remez_arg->field_type == BOSON) {
    getPFE(remez_arg->residue, remez_arg->pole, &(remez_arg->norm));
    getIPFE(remez_arg->residue_inv, remez_arg->pole_inv, &(remez_arg->norm_inv));
  } else {
    getIPFE(remez_arg->residue, remez_arg->pole, &(remez_arg->norm));
    getPFE(remez_arg->residue_inv, remez_arg->pole_inv, &(remez_arg->norm_inv));
  }

  remez_arg->error = error;
  time += dclock();
  print_time(cname,fname,time);

}
// Парсит всю формулу (которая может содержать несоклько уравнений)
CFormula ParseFormula( const std::string& text ) {
	std::vector<std::string> equations( 1 );
	std::string spaces = " \t\n\r";
	for( int i = 0; i < static_cast<int>( text.size() ); ++i ) {
		if( spaces.find( text[i] ) != std::string::npos ) {
			continue;
		}
		if( text[i] == ',' && !equations.back().empty() ) {
			equations.push_back( std::string() );
			continue;
		}
		equations.back().push_back( text[i] );
	}
	CheckEquationsCorrectness( equations );
	int spaceDimension = GetSpaceDimension( equations );
	assert( spaceDimension >= 2 );
	int plotDimension = GetPlotDimension( equations );
	std::vector<char> variables = GetEquationsVariables( equations );
	CFormula formula( spaceDimension, plotDimension, variables );
	for( int i = 0; i < static_cast<int>( equations.size() ); ++i ) {
		formula.AddEquation( ParseEquation( equations[i] ) );
	}
	return formula;
}
Exemple #4
0
// Generate the rational approximation x^(pnum/pden)
double AlgRemez::generateApprox(int num_degree, int den_degree, 
				unsigned long pnum, unsigned long pden,
				int a_len, double *a_param, int *a_pow)
{
  char *fname = "generateApprox(int, unsigned long, unsigned long)";

  printf("Degree of the approximation is (%d,%d)\n", num_degree, den_degree);
  printf("Approximating the function x^(%d/%d)\n", pnum, pden);

  // Reallocate arrays, since degree has changed
  if (num_degree != n || den_degree != d) allocate(num_degree,den_degree);

  if (a_len > SUM_MAX) {
    printf("Error: a_length > SUM_MAX");
    exit(0);
  }

  step = new bigfloat[num_degree+den_degree+2];

  a_length = a_len;
  for (int j=0; j<a_len; j++) {
    a[j]= a_param[j];
    a_power[j] = a_pow[j];
  }

  power_num = pnum;
  power_den = pden;
  spread = 1.0e37;
  iter = 0;

  n = num_degree;
  d = den_degree;
  neq = n + d + 1;

  initialGuess();
  stpini(step);

  while (spread > tolerance) { //iterate until convergance

    if (iter++%100==0) 
      printf("Iteration %d, spread %e delta %e\n", 
	     iter-1,(double)spread,(double)delta);

    equations();
    if (delta < tolerance) {
      printf("Delta too small, try increasing precision\n");
      exit(0);
    }

    search(step);

  }

  int sign;
  double error = (double)getErr(mm[0],&sign);
  printf("Converged at %d iterations, error = %e\n",iter,error);

  // Once the approximation has been generated, calculate the roots
  if(!root()) {
    printf("Root finding failed\n");
  } else {
    foundRoots = 1;
  }
  
  delete [] step;

  // Return the maximum error in the approximation
  return error;
}