Descent Class Reference

#include <som.h>

Public Member Functions
	Descent (const double _initial=1, const double _final=0)
virtual	~Descent ()
virtual double	operator() (const unsigned _step, const unsigned _nSteps) const
virtual void	printSelf (std::ostream &_os) const
virtual void	readSelf (std::istream &_is)
virtual void	saveObject (std::ostream &_os) const
virtual void	loadObject (std::istream &_is)

Protected Attributes
double	initial
double	final

Friends
std::ostream &	operator<< (std::ostream &_os, const Descent &_desc)
std::istream &	operator>> (std::istream &_is, Descent &_desc)

Detailed Description

This class implements a descent from an initial value to a final one in a number of steps. The transition is linear by default. It's used to decrease alpha and the radius of neighborhood during training of SOM.

Definition at line 48 of file som.h.

Constructor & Destructor Documentation

Descent()

Descent::Descent ( const double  _initial = 1, const double  _final = 0  )

inline

Constructor Parameter: _initial Parameter: _final

Definition at line 56 of file som.h.

            : initial(_initial), final(_final)
    {}

~Descent()

virtual Descent::~Descent ( )

inlinevirtual

Destructor

Definition at line 62 of file som.h.

{}

Member Function Documentation

loadObject()

void Descent::loadObject ( std::istream &  _is )

virtual

Loads the Descent class from a stream. this method can be used to load the status of the class. Parameter: _is The output stream

Definition at line 325 of file som.cpp.

{
    readSelf(_is);
}

operator()()

double Descent::operator() ( const unsigned  _step, const unsigned  _nSteps  ) const

virtual

Returns the function value associated a step if the transition from the initial value to the final value es made in _nSteps steps Parameter: _step The actual step Parameter: _nsteps The number of steps to reach the final val from the initial one

Definition at line 266 of file som.cpp.

{
    if (_nSteps == 0 || initial == final || _step >= _nSteps)
        return final;
    else
        return final + ((initial - final) *
                        ((double)(_nSteps - _step) / (double)_nSteps));
}

printSelf()

void Descent::printSelf ( std::ostream &  _os ) const

virtual

Standard output for a Descent class Parameter: _os The output stream

Definition at line 280 of file som.cpp.

{
    _os << initial << std::endl;
    _os << final << std::endl;
}

readSelf()

void Descent::readSelf ( std::istream &  _is )

virtual

Standard input for a Descent class Parameter: _is The input stream

Definition at line 290 of file som.cpp.

{
    try
    {
        if (_is)
            _is >> initial;
        if (_is)
            _is >> final;
    }
    catch (std::exception& e)
    {
        std::stringstream msg;
        msg << e.what() << std::endl << "Error reading Descent class";
        throw std::runtime_error(msg.str());
    }

}

saveObject()

void Descent::saveObject ( std::ostream &  _os ) const

virtual

Saves the Descent class into a stream. this method can be used to save the status of the class. Parameter: _os The output stream

Definition at line 314 of file som.cpp.

{
    printSelf(_os);
}

Friends And Related Function Documentation

operator<<

std::ostream& operator<< ( std::ostream &  _os, const Descent &  _desc  )

friend

Standard output for a Descent class Parameter: _os The output stream Parameter: _desc The class

Definition at line 108 of file som.h.

    {
        _desc.printSelf(_os);
        return _os;
    };

operator>>

std::istream& operator>> ( std::istream &  _is, Descent &  _desc  )

friend

Standard input for a Descent class Parameter: _is The input stream Parameter: _desc The class

Definition at line 119 of file som.h.

    {
        _desc.readSelf(_is);
        return _is;
    };

Member Data Documentation

final

double Descent::final

protected

Definition at line 128 of file som.h.

initial

double Descent::initial

protected

Definition at line 123 of file som.h.

---

The documentation for this class was generated from the following files:

• xmipp/libraries/classification/som.h
• xmipp/libraries/classification/som.cpp