classias::train::truncated_gradient_multi< error_tmpl > Class Template Reference

Inheritance diagram for classias::train::truncated_gradient_multi< error_tmpl >:

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Detailed Description

template<class error_tmpl>
class classias::train::truncated_gradient_multi< error_tmpl >

Truncated gradient for multi-class classification.

Parameters:

error_tmpl

The type of the error (loss) function.

Public Types
typedef error_tmpl	error_type
	The type implementing an error function.
typedef error_type::model_type	model_type
	The type implementing a model (weight vector for features).
typedef model_type::value_type	value_type
	The type representing a value.
typedef truncated_gradient_base< error_tmpl >	base_class
	A synonym of the base class.
typedef truncated_gradient_multi< error_tmpl >	this_class
	A synonym of this class.
Public Member Functions
template<class iterator_type, class feature_generator_type>
void	update (iterator_type it, feature_generator_type &fgen)
	Receives a training instance and updates feature weights.
template<class iterator_type>
void	update (iterator_type first, iterator_type last)
	Receives multiple training instances and updates feature weights.
Protected Member Functions
template<class feature_generator_type, class iterator_type>
void	update_weights (int l, feature_generator_type &fgen, iterator_type first, iterator_type last, value_type delta)
	Adds a value to weights associated with a feature vector.
template<class feature_generator_type, class iterator_type>
void	apply_penalty (int l, feature_generator_type &fgen, iterator_type first, iterator_type last)
	Applies L1 penalties to the feature weights.

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Member Function Documentation

template<class error_tmpl>

template<class iterator_type, class feature_generator_type>

void classias::train::truncated_gradient_multi< error_tmpl >::update	(	iterator_type	it,
		feature_generator_type &	fgen
	)			[inline]

Receives a training instance and updates feature weights.

Parameters:

	it	An interator for the training instance.
	fgen	The feature generator.

Returns:

value_type The loss computed for the instance.

template<class error_tmpl>

template<class iterator_type>

void classias::train::truncated_gradient_multi< error_tmpl >::update	(	iterator_type	first,
		iterator_type	last
	)			[inline]

Receives multiple training instances and updates feature weights.

Parameters:

	first	The iterator pointing to the first instance.
	last	The iterator pointing just beyond the last instance.

Returns:

value_type The loss computed for the instances.

template<class error_tmpl>

template<class feature_generator_type, class iterator_type>

void classias::train::truncated_gradient_multi< error_tmpl >::update_weights	(	int	l,
		feature_generator_type &	fgen,
		iterator_type	first,
		iterator_type	last,
		value_type	delta
	)			[inline, protected]

Adds a value to weights associated with a feature vector.

Parameters:

	l	The candidate index.
	fgen	The feature generator.
	first	The iterator pointing to the first element of the feature vector.
	last	The iterator pointing just beyond the last element of the feature vector.
	delta	The value to be added to the weights.

template<class error_tmpl>

template<class feature_generator_type, class iterator_type>

void classias::train::truncated_gradient_multi< error_tmpl >::apply_penalty	(	int	l,
		feature_generator_type &	fgen,
		iterator_type	first,
		iterator_type	last
	)			[inline, protected]

Applies L1 penalties to the feature weights.

This function applies L1 penalties to the weights in a feature vector.

Parameters:

	l	The candidate index.
	fgen	The feature generator.
	first	The iterator pointing to the first element of the feature vector.
	last	The iterator pointing just beyond the last element of the feature vector.

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Copyright (c) 2002-2009 by Naoaki Okazaki
Mon Dec 28 23:41:08 2009