FST::Criterion_Wrapper_Bias_Estimate< RETURNTYPE, SUBSET, CLASSIFIER, DATAACCESSOR > Class Template Reference

Wrapper Bias Evaluator - returns bias estimate (difference of classifier accuracy on training and validation data parts). More...

#include <criterion_wrapper_bias_estimate.hpp>

Inheritance diagram for FST::Criterion_Wrapper_Bias_Estimate< RETURNTYPE, SUBSET, CLASSIFIER, DATAACCESSOR >:

[legend]

Collaboration diagram for FST::Criterion_Wrapper_Bias_Estimate< RETURNTYPE, SUBSET, CLASSIFIER, DATAACCESSOR >:

[legend]

List of all members.

Public Types
typedef Criterion_Wrapper < RETURNTYPE, SUBSET, CLASSIFIER, DATAACCESSOR >	parent
typedef boost::shared_ptr < CLASSIFIER >	PClassifier
typedef boost::shared_ptr < DATAACCESSOR >	PDataAccessor
typedef boost::shared_ptr< SUBSET >	PSubset
Public Member Functions
virtual bool	evaluate (RETURNTYPE &result, const PSubset sub)
	trains then tests then returns estimated classifcation accuracy
RETURNTYPE	getBiasEstimate () const
	returns estimated bias average over all evaluate() invocations since the last reset
void	resetBiasEstimate ()
Criterion_Wrapper_Bias_Estimate *	clone () const
Criterion_Wrapper_Bias_Estimate *	sharing_clone () const
Criterion_Wrapper_Bias_Estimate *	stateless_clone () const
virtual std::ostream &	print (std::ostream &os) const
Protected Member Functions
	Criterion_Wrapper_Bias_Estimate (const Criterion_Wrapper_Bias_Estimate &cwbe)
Protected Attributes
RETURNTYPE	_collected_bias_estimate
RETURNTYPE	_collected_bias_count

---

Detailed Description

template<class RETURNTYPE, class SUBSET, class CLASSIFIER, class DATAACCESSOR>
class FST::Criterion_Wrapper_Bias_Estimate< RETURNTYPE, SUBSET, CLASSIFIER, DATAACCESSOR >

Wrapper Bias Evaluator - returns bias estimate (difference of classifier accuracy on training and validation data parts).

Wraps Classifier objects to serve as secondary feature selection criterion. Trains classifier on training data, then evaluates the difference between estimated classification accuracy on training data and test data. Especially in small-sample scenarios a considerable difference (i.e., bias) can be expected. Large bias can be viewed as a sign of overfitting and can thus be used as indicator of feature selection process failure.

Note:

Expect at least 2x slower operation than that of Criterion_Wrapper.

Examples:

demo56.cpp.

---

Member Function Documentation

template<class RETURNTYPE , class SUBSET , class CLASSIFIER , class DATAACCESSOR >

Criterion_Wrapper_Bias_Estimate< RETURNTYPE, SUBSET, CLASSIFIER, DATAACCESSOR > * FST::Criterion_Wrapper_Bias_Estimate< RETURNTYPE, SUBSET, CLASSIFIER, DATAACCESSOR >::clone

(

)

const [inline, virtual]

create 1:1 independent clone of the current object

Reimplemented from FST::Criterion_Wrapper< RETURNTYPE, SUBSET, CLASSIFIER, DATAACCESSOR >.

template<class RETURNTYPE, class SUBSET, class CLASSIFIER, class DATAACCESSOR>

Criterion_Wrapper_Bias_Estimate* FST::Criterion_Wrapper_Bias_Estimate< RETURNTYPE, SUBSET, CLASSIFIER, DATAACCESSOR >::sharing_clone

(

)

const [inline, virtual]

create equivalent clone of the current object, parmitting read-only access to structures in the source object (allows referencing instead of copying of large memory structures). may be faster and save space but requires more caution with respect to concurrency Use example: Data_Accessor memory data representation cloning

Reimplemented from FST::Criterion_Wrapper< RETURNTYPE, SUBSET, CLASSIFIER, DATAACCESSOR >.

template<class RETURNTYPE, class SUBSET, class CLASSIFIER, class DATAACCESSOR>

Criterion_Wrapper_Bias_Estimate* FST::Criterion_Wrapper_Bias_Estimate< RETURNTYPE, SUBSET, CLASSIFIER, DATAACCESSOR >::stateless_clone

(

)

const [inline, virtual]

create clone of the current object, ignoring internal temporary structures to save speed. Does not replicate exact object state. The clone must be used carefully in a way that ensures internal structure re-initialization Use example: Data_Splitter cloning or Classifier_SVM cloning due to inability to clone external structures defined in LibSVM

Reimplemented from FST::Criterion_Wrapper< RETURNTYPE, SUBSET, CLASSIFIER, DATAACCESSOR >.

---

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

• criterion_wrapper_bias_estimate.hpp