详细描述

The class implements the gradient descend method.

Given a target variable, \(w\), and its gradient, \(d\), without gradient correction (eg, momentum correction), this class performs the following update.

\[ w^{new} = w - \lambda d \]

, where \(\lambda\) is a learning rate.

在文件 GradientDescendUpdater.h 第 48 行定义.

类 GradientDescendUpdater 继承关系图:

[图例]

Public 成员函数
	GradientDescendUpdater ()

virtual	~GradientDescendUpdater ()

virtual void	update_variable (SGVector< float64_t > variable_reference, SGVector< float64_t > raw_negative_descend_direction, float64_t learning_rate)

virtual void	update_context (CMinimizerContext *context)

virtual void	load_from_context (CMinimizerContext *context)

virtual void	set_descend_correction (DescendCorrection *correction)

virtual bool	enables_descend_correction ()

Protected 成员函数
virtual float64_t	get_negative_descend_direction (float64_t variable, float64_t gradient, index_t idx, float64_t learning_rate)

Protected 属性
DescendCorrection *	m_correction

构造及析构函数说明

GradientDescendUpdater ( )

在文件 GradientDescendUpdater.cpp 第 36 行定义.

~GradientDescendUpdater ( )

virtual

在文件 GradientDescendUpdater.cpp 第 42 行定义.

成员函数说明

virtual bool enables_descend_correction ( )

virtualinherited

Do we enable descend correction?

返回: whether we enable descend correction

在文件 DescendUpdaterWithCorrection.h 第 145 行定义.

float64_t get_negative_descend_direction	(	float64_t	variable,
		float64_t	gradient,
		index_t	idx,
		float64_t	learning_rate
	)

protectedvirtual

Get the negative descend direction given current variable and gradient

It will be called at update_variable()

参数

variable	current variable
gradient	current gradient
idx	the index of the variable
learning_rate	learning rate

返回: negative descend direction (that is, the given gradient in the class)

实现了 DescendUpdaterWithCorrection.

在文件 GradientDescendUpdater.cpp 第 50 行定义.

virtual void load_from_context ( CMinimizerContext * context )

virtualinherited

Load the given context object to restore mutable variables

This method will be called by FirstOrderMinimizer::load_from_context(CMinimizerContext* context)

参数

context a context object

实现了 DescendUpdater.

被 AdaDeltaUpdater, RmsPropUpdater , 以及 AdaGradUpdater 重载.

在文件 DescendUpdaterWithCorrection.h 第 124 行定义.

virtual void set_descend_correction ( DescendCorrection * correction )

virtualinherited

Set the type of descend correction

参数

correction the type of descend correction

在文件 DescendUpdaterWithCorrection.h 第 135 行定义.

virtual void update_context ( CMinimizerContext * context )

virtualinherited

Update a context object to store mutable variables used in descend update

This method will be called by FirstOrderMinimizer::save_to_context()

参数

context a context object

实现了 DescendUpdater.

被 AdaDeltaUpdater, RmsPropUpdater , 以及 AdaGradUpdater 重载.

在文件 DescendUpdaterWithCorrection.h 第 110 行定义.

virtual void update_variable	(	SGVector< float64_t >	variable_reference,
		SGVector< float64_t >	raw_negative_descend_direction,
		float64_t	learning_rate
	)

virtualinherited

Update the target variable based on the given negative descend direction

Note that this method will update the target variable in place. This method will be called by FirstOrderMinimizer::minimize()

参数

variable_reference	a reference of the target variable
raw_negative_descend_direction	the negative descend direction given the current value
learning_rate	learning rate

实现了 DescendUpdater.

被 AdaDeltaUpdater, RmsPropUpdater , 以及 AdaGradUpdater 重载.

在文件 DescendUpdaterWithCorrection.h 第 67 行定义.

类成员变量说明

DescendCorrection* m_correction

protectedinherited

descend correction object

在文件 DescendUpdaterWithCorrection.h 第 165 行定义.

该类的文档由以下文件生成:

详细描述

Public 成员函数

Protected 成员函数

Protected 属性

构造及析构函数说明

成员函数说明

类成员变量说明