DGtal::detail Namespace Reference

Data Structures
struct	HasNestedType
	Aim: Checks whether type has a nested type called 'Type' or not. NB: from en.wikipedia.org/wiki/Substitution_failure_is_not_an_error. More...
struct	IsCirculator
	Aim: Checks whether type is a circular or a classical iterator. NB: from en.wikipedia.org/wiki/Substitution_failure_is_not_an_error. More...
struct	IsCirculator< IC, true >
struct	IteratorCirculatorTypeImpl
	Aim: Defines the Iterator or Circulator type as a nested type according to the value of b. More...
struct	IteratorCirculatorTypeImpl< true >
struct	LabelledMapMemFunctor
class	PosIndepScaleIndepSCEstimator
class	PosIndepScaleDepSCEstimator
class	PosDepScaleIndepSCEstimator
class	PosDepScaleDepSCEstimator
struct	TangentAngleFromDSS
struct	NormalizedTangentVectorFromDSS
struct	TangentVectorFromDSS
struct	CurvatureFromDCA
struct	CurvatureFromDCA< false >
struct	NormalVectorFromDCA
struct	TangentVectorFromDCA
struct	DistanceFromDCA
struct	CurvatureFromDSSLength
struct	CurvatureFromDSSLengthAndWidth
class	CurvatureFromDSSBaseEstimator

Functions
template<typename IC >
bool	isNotEmpty (const IC &itb, const IC &ite, IteratorType)
template<typename IC >
bool	isNotEmpty (const IC &c1, const IC &c2, CirculatorType)
template<typename TData >
std::pair< unsigned int, unsigned int >	argminLabelledMapMemoryUsageForGeometricDistribution (unsigned int L, double prob_no_data, double prob_one_data)

---

Function Documentation

template<typename TData >

std::pair< unsigned int, unsigned int > DGtal::detail::argminLabelledMapMemoryUsageForGeometricDistribution	(	unsigned int	L,
		double	prob_no_data,
		double	prob_one_data
	)

Tries to find the best values N and M which will minimized the memory usage of a LabelledMap, for the distribution specified by the parameters.

Template Parameters:

TValue

the type of data that will be stored.

Parameters:

L	the total number of labels.
prob_no_data	Probability that there is no data at this location.
prob_one_data	If there is a possibility to have a data, this probability is used to define a geometric distribution that defines the number of data (ie valid labels) at this place. The smaller, the higher is the expectation. 0.5 means E(X) = 1.

Returns:

the pair (N,M) that minimizes the memory usage of a LabelledMap for the given distribution.

Definition at line 1225 of file LabelledMap.ih.

References DGtal::detail::LabelledMapMemFunctor::fctNM().

{
  unsigned int sL = 2 * ( ( ( L - 1 ) / 16 ) + 1 ); // word of 16bits
  // std::cerr << "L=" << L  << " sL=" << sL << std::endl;
  LabelledMapMemFunctor F( prob_one_data, prob_no_data, sL, sizeof( TData ),
                           sizeof( TData* ), 2 );
  double m = -1.0;
  unsigned int Nopt = 0;
  unsigned int Mopt = 0;
  for ( unsigned int N = 1; N < L; ++N )
    for ( unsigned int M = 2; M < (L-N); ++M )
      {
        // std::cerr << "Fmem(" << N << "," << M << ")=" 
        //           << F.fctNM( N, M ) << std::endl;
        if ( ( m < 0.0 ) || ( F.fctNM( N, M ) < m ) )
          {
            Nopt = N; Mopt = M; 
            m = F.fctNM( Nopt, Mopt );
          }
      }
  return std::make_pair( Nopt, Mopt );
}

template<typename IC >

bool DGtal::detail::isNotEmpty ( const IC &  itb, const IC &  ite, IteratorType    )

inline

Definition at line 57 of file IteratorFunctions.h.

Referenced by DGtal::detail::PosIndepScaleIndepSCEstimator< DSSComputer, detail::TangentAngleFromDSS >::eval(), DGtal::detail::PosIndepScaleDepSCEstimator< DCAComputer, detail::CurvatureFromDCA< isCCW > >::eval(), DGtal::detail::PosDepScaleIndepSCEstimator< DCAComputer, detail::TangentVectorFromDCA >::eval(), DGtal::detail::PosDepScaleDepSCEstimator< DCAComputer, detail::DistanceFromDCA >::eval(), and DGtal::detail::CurvatureFromDSSBaseEstimator< DSSComputer, detail::CurvatureFromDSSLength >::eval().

                                                                {
    return (itb != ite);
  }

template<typename IC >

bool DGtal::detail::isNotEmpty ( const IC &  c1, const IC &  c2, CirculatorType    )

inline

Definition at line 63 of file IteratorFunctions.h.

                                                               {
// using isValid method does not work with reverse circulator 
//(generally speaking adapters of circulators that does not have any isValid method)
//    return ( ( c1.isValid() ) && ( c2.isValid() ) );  
    IC c; //c is not valid
    return ( (c1 != c) && (c2 != c) ); 
  }