convergents.cpp File Reference

#include <iostream>
#include "DGtal/arithmetic/LighterSternBrocot.h"

Go to the source code of this file.

Functions
void	usage (int, char **argv)
int	main (int argc, char **argv)

Detailed Description

Author

Jacques-Olivier Lachaud (jacqu.nosp@m.es-o.nosp@m.livie.nosp@m.r.la.nosp@m.chaud.nosp@m.@uni.nosp@m.v-sav.nosp@m.oie..nosp@m.fr ) Laboratory of Mathematics (CNRS, UMR 5127), University of Savoie, France

Date

2012/02/06

An example file named convergents.

This file is part of the DGtal library.

Definition in file convergents.cpp.

Function Documentation

main()

int main	(	int	argc,
		char **	argv
	)

Main.

[convergents-types]

[convergents-types]

[convergents-instantiation]

[convergents-instantiation]

[convergents-cfrac]

[convergents-cfrac]

[convergents-convergents]

[convergents-convergents]

Definition at line 55 of file convergents.cpp.

{
  if ( argc < 3 )
    {
      usage( argc, argv );
      return 1;
    }
 
  typedef LighterSternBrocot<DGtal::int64_t, DGtal::int64_t, StdMapRebinder> SB; // the type of the Stern-Brocot tree
  typedef SB::Fraction Fraction; // the type for fractions
  typedef Fraction::ConstIterator ConstIterator; // the iterator type for visiting quotients
  typedef Fraction::Value Value; // the value of the iterator, a pair (quotient,depth).
 
  DGtal::int64_t p = atoll( argv[ 1 ] );
  DGtal::int64_t q = atoll( argv[ 2 ] );
  Fraction f( p, q ); // fraction p/q
 
  // Visit quotients u_k as pair (u_k,k)
  std::cout << "z = ";
  ConstIterator itbegin = f.begin(), itend = f.end();
  for ( ConstIterator it = itbegin; it != itend; ++it )
    {
      Value u = *it;
      std::cout << ( ( it == itbegin ) ? "[" : "," )
                << u.first;
    }
  std::cout << "]" << std::endl;
 
  Fraction g;         // fraction null, 0/0, invalid
  for ( ConstIterator it = itbegin; it != itend; ++it )
    {
      Value u = *it;
      std::cout << "z_" << u.second << " = ";
      g.push_back( u ); // add (u_i,i) to existing fractions
      std::cout << g.p() << " / " << g.q() << std::endl;
    }
  return 0;
}

usage()

void usage	(	int	,
		char **	argv
	)

Definition at line 46 of file convergents.cpp.

{
  std::cerr << "Usage: " << argv[ 0 ] << " <p> <q>" << std::endl;
  std::cerr << "\t - computes the successive convergent of the fraction p / q." << std::endl;
}