lbann::ltfb::TruncationSelectionExchange Class Reference

#include <truncation_selection_exchange.hpp>

Inheritance diagram for lbann::ltfb::TruncationSelectionExchange:

Collaboration diagram for lbann::ltfb::TruncationSelectionExchange:

Public Types
enum	metric_strategy { metric_strategy::LOWER_IS_BETTER, metric_strategy::HIGHER_IS_BETTER }

Public Member Functions
void	select_next (model &m, ltfb::LTFBExecutionContext &ctxt, data_coordinator &dc) const final
	Engage in a ranked tournament with a population of trainers. More...
Life-cycle management
	TruncationSelectionExchange (std::string metric_name, metric_strategy winner_strategy, int truncation_k)
	Constructor. More...
	TruncationSelectionExchange (std::unordered_map< std::string, metric_strategy > metrics, int truncation_k)
	Constructor. More...
	~TruncationSelectionExchange ()=default
	TruncationSelectionExchange (TruncationSelectionExchange const &other)
Public Member Functions inherited from lbann::Cloneable< TruncationSelectionExchange, MetaLearningStrategy >
std::unique_ptr< TruncationSelectionExchange >	clone () const
	Return an exception-safe, memory-safe copy of this object. More...

Private Member Functions
EvalType	evaluate_model (model &m, LTFBExecutionContext &ctxt, data_coordinator &dc) const
	Get the value of the given metric from the model. More...

Private Attributes
std::unordered_map< std::string, metric_strategy >	m_metrics
	The list of metric/strategy pairs. More...
int	m_truncation_k

Detailed Description

A variant of classic LTFB or exploitation mechanism in population-based training. All trainers in the population set are ranked using specified evaluation metric. Model parameters, training hyperparameters and or topologies of any trainer in the bottom rank is replaced by that of a (random) trainer in the top rank.

Definition at line 50 of file truncation_selection_exchange.hpp.

Member Enumeration Documentation

metric_strategy

enum lbann::ltfb::TruncationSelectionExchange::metric_strategy

strong

Enumerator
LOWER_IS_BETTER
HIGHER_IS_BETTER

Definition at line 54 of file truncation_selection_exchange.hpp.

Constructor & Destructor Documentation

TruncationSelectionExchange() [1/3]

lbann::ltfb::TruncationSelectionExchange::TruncationSelectionExchange	(	std::string	metric_name,
		metric_strategy	winner_strategy,
		int	truncation_k
	)

Constructor.

Parameters

[in]	metric_name	The name of the metric to use for evaluation. A metric with this name must exist in the model passed to apply().
[in]	winner_strategy	Strategy for determining the winner of a tournament.
[in]	truncation_k	Partitions ranking list to top(winners)/bottom(losers)

TruncationSelectionExchange() [2/3]

lbann::ltfb::TruncationSelectionExchange::TruncationSelectionExchange	(	std::unordered_map< std::string, metric_strategy >	metrics,
		int	truncation_k
	)

Constructor.

Parameters

[in]	metrics	The metric/strategy pairs. A metric with each given name must exist in the model passed to apply().
[in]	truncation_k	Partitions ranking list to top(winners)/bottom(losers)

~TruncationSelectionExchange()

lbann::ltfb::TruncationSelectionExchange::~TruncationSelectionExchange ( )

default

TruncationSelectionExchange() [3/3]

lbann::ltfb::TruncationSelectionExchange::TruncationSelectionExchange

(

TruncationSelectionExchange const &

other

)

Member Function Documentation

evaluate_model()

EvalType lbann::ltfb::TruncationSelectionExchange::evaluate_model ( model &  m, LTFBExecutionContext &  ctxt, data_coordinator &  dc  ) const

private

Get the value of the given metric from the model.

select_next()

void lbann::ltfb::TruncationSelectionExchange::select_next ( model &  m, ltfb::LTFBExecutionContext &  ctxt, data_coordinator &  dc  ) const

final

Engage in a ranked tournament with a population of trainers.

Parameters

[in,out]	m	On input, the locally computed model. On output, the selected (winning model) with respect to the tournament.
[in,out]	ctxt	The execution context for the outer LTFB wrapper.
[in,out]	dc	The data source for the tournament.

Member Data Documentation

m_metrics

std::unordered_map<std::string, metric_strategy> lbann::ltfb::TruncationSelectionExchange::m_metrics

private

The list of metric/strategy pairs.

Each metric gets its own strategy. Note, only one metric and strategy pair is currently supported. List (map) is for compatibility with classic LTFB (RPE) And as a placeholder for when multiple metrics are needed.

Definition at line 118 of file truncation_selection_exchange.hpp.

m_truncation_k

int lbann::ltfb::TruncationSelectionExchange::m_truncation_k

private

Definition at line 122 of file truncation_selection_exchange.hpp.

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

• truncation_selection_exchange.hpp