RDInfoTheory::InfoBitRanker Class Reference

#include <InfoBitRanker.h>

Public Types
enum	InfoType { ENTROPY = 1 , BIASENTROPY = 2 , CHISQUARE = 3 , BIASCHISQUARE = 4 }
	the type of measure for information More...

Public Member Functions
	InfoBitRanker (unsigned int nBits, unsigned int nClasses, InfoType infoType=InfoBitRanker::ENTROPY)
	Constructor.
	~InfoBitRanker ()
void	accumulateVotes (const ExplicitBitVect &bv, unsigned int label)
	Accumulate the votes for all the bits turned on in a bit vector.
void	accumulateVotes (const SparseBitVect &bv, unsigned int label)
double *	getTopN (unsigned int num)
	Returns the top n bits ranked by the information metric.
unsigned int	getNumInstances () const
	return the number of labelled instances(examples) or fingerprints seen so far
unsigned int	getNumClasses () const
	return the number of classes
void	setBiasList (RDKit::INT_VECT &classList)
	Set the classes to which the entropy calculation should be biased.
void	setMaskBits (RDKit::INT_VECT &maskBits)
	Set the bits to be used as a mask.
void	writeTopBitsToStream (std::ostream *outStream) const
	Write the top N bits to a stream.
void	writeTopBitsToFile (const std::string &fileName) const
	Write the top bits to a file.

Detailed Description

Definition at line 87 of file InfoBitRanker.h.

Member Enumeration Documentation

InfoType

enum RDInfoTheory::InfoBitRanker::InfoType

the type of measure for information

Enumerator
ENTROPY
BIASENTROPY
CHISQUARE
BIASCHISQUARE

Definition at line 92 of file InfoBitRanker.h.

Constructor & Destructor Documentation

InfoBitRanker()

RDInfoTheory::InfoBitRanker::InfoBitRanker ( unsigned int  nBits, unsigned int  nClasses, InfoType  infoType = InfoBitRanker::ENTROPY  )

inline

Constructor.

ARGUMENTS:

• nBits: the dimension of the bit vectors or the fingerprint length
• nClasses: the number of classes used in the classification problem (e.g. active, moderately active, inactive etc.). It is assumed that the classes are numbered from 0 to (nClasses - 1)
• infoType: the type of information metric

Definition at line 111 of file InfoBitRanker.h.

~InfoBitRanker()

RDInfoTheory::InfoBitRanker::~InfoBitRanker ( )

inline

Definition at line 128 of file InfoBitRanker.h.

Member Function Documentation

accumulateVotes() [1/2]

void RDInfoTheory::InfoBitRanker::accumulateVotes	(	const ExplicitBitVect &	bv,
		unsigned int	label
	)

Accumulate the votes for all the bits turned on in a bit vector.

ARGUMENTS:

• bv : bit vector that supports [] operator
• label : the class label for the bit vector. It is assumed that 0 <= class < nClasses

accumulateVotes() [2/2]

void RDInfoTheory::InfoBitRanker::accumulateVotes	(	const SparseBitVect &	bv,
		unsigned int	label
	)

getNumClasses()

unsigned int RDInfoTheory::InfoBitRanker::getNumClasses ( ) const

inline

return the number of classes

Definition at line 169 of file InfoBitRanker.h.

getNumInstances()

unsigned int RDInfoTheory::InfoBitRanker::getNumInstances ( ) const

inline

return the number of labelled instances(examples) or fingerprints seen so far

Definition at line 164 of file InfoBitRanker.h.

getTopN()

double * RDInfoTheory::InfoBitRanker::getTopN

(

unsigned int

num

)

Returns the top n bits ranked by the information metric.

This is actually the function where most of the work of ranking is happening

Parameters

num	the number of top ranked bits that are required

Returns

a pointer to an information array. The client should not delete this

setBiasList()

void RDInfoTheory::InfoBitRanker::setBiasList

(

RDKit::INT_VECT &

classList

)

Set the classes to which the entropy calculation should be biased.

This list contains a set of class ids used when in the BIASENTROPY mode of ranking bits. In this mode, a bit must be correllated higher with one of the biased classes than all the other classes. For example, in a two class problem with actives and inactives, the fraction of actives that hit the bit has to be greater than the fraction of inactives that hit the bit

ARGUMENTS: classList - list of class ids that we want a bias towards

setMaskBits()

void RDInfoTheory::InfoBitRanker::setMaskBits

(

RDKit::INT_VECT &

maskBits

)

Set the bits to be used as a mask.

If this function is called, only the bits which are present in the maskBits list will be used.

ARGUMENTS: maskBits - the bits to be considered

writeTopBitsToFile()

void RDInfoTheory::InfoBitRanker::writeTopBitsToFile

(

const std::string &

fileName

)

const

Write the top bits to a file.

writeTopBitsToStream()

void RDInfoTheory::InfoBitRanker::writeTopBitsToStream

(

std::ostream *

outStream

)

const

Write the top N bits to a stream.

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

• InfoBitRanker.h