NumSelectGeneticBC - Implementation class for genetic algorithm feature subset selection.

Developer Documentation

Centre for Vision, Speech & Signal Processing

Comments:
Implementation class for selecting a feature subset using a genetic algorithm. The NumSelectGeneticC handle class should be used.

Parent Classes:

NumSelectBC

GeneticAlgorithmC

Variables:

UIntT _iterations;
IntSArray1dC _list;
NumVLDataSetC _data;
NumClassifySupervisedC _classifier;
NumErrorC _error;
NumPerformanceC _performance;

Methods:

IntSArray1dC gene2list(IntSArray1dC str) const

Converts a gene to a list of enabled features
This provides an interface between the gene bitstring representation and a list of features which can be used for extracting the feature subset.

RealT EvaluateFitness(const IntSArray1dC & gene)

Evaluates fitness of the given gene bitstring

NumSelectGeneticBC(UIntT poolSize,UIntT iterations,RealT probMutation,RealT probCrossover)

Class constructor.

poolSize	number of genes in the pool at each generation. Should be odd.
iterations	number of generations to compute
probMutation	chance per gene of mutation occuring
probCrossover	chance per gene par of crossover occuring

NumSelectGeneticBC(istream & in)

Constructs from stream and provides class name

NumSelectGeneticBC(const NumSelectGeneticBC & oth)

Copy Constructor

BodyRefCounterVC & Copy() const

Makes a deep copy and is virtual

VectorC Evaluate(const VectorC & X) const

Evaluate Y=f(X)

void Design(const NumVLDataSetC & data,NumClassifySupervisedC & classifier,const NumErrorC & error,const NumPerformanceC & performance)

Used to determine which is best feature subset using genetic algorithm

const StringC GetInfo() const

Prints derived class information

BooleanT Save(ostream & out) const

Writes object to stream, can be loaded using constructor

#include "amma/Num/NumSelectB.hh"

void Design(const NumVLDataSetC & data,NumClassifySupervisedC & classifier,const NumErrorC & error,const NumPerformanceC & performance)

Used to determine which is best feature subset

data	data set with feature vectors and correct labels
classifier	classifier to use for testing performance
performance	method for estimating PMC

A derived class must provide a method for choosing a subset of features which minimises the PMC for the given combination of classifier, error counting method and algorithm for performance evaluation.

const StringC GetInfo() const

Prints derived class information

BooleanT Save(ostream & out) const

Writes object to stream, can be loaded using constructor

#include "amma/GeneticAlgorithm.hh"

void SetChromosomes(UIntT chromosomeSize,UIntT minChromosomes,UIntT maxChromosomes)

Sets chromosome characteristics as in constructor

void RandomPool(const IntSArray1dC & initialGene)

Generates a random pool of genes.

initialGene	starting point or elite gene from previous generation

Generates a pool containing random genes inserts the initialGene into the pool to ensure its survival.

void Generation()

Performs one generation of evolution
This involves evaluation, selection, mutation and crossover.

const IntSArray1dC GetBestGene() const

Returns the best gene as a bit string

void Save(ostream & out) const

Writes object to stream, cna be loaded using constructor

RealT EvaluateFitness(const IntSArray1dC & gene)

Determine fitness of the given gene bitstring
Must be overloaded in derived class to calculated fitness given a gene string

void Evaluation()

Performs evaluation of the gene pool

void Selection()

Creates next generation gene pool using selection process

void Mutation()

Performs mutation of the genes

void Crossover()

Performs crossover of the genes

void Crossover(GeneC & mum,GeneC & dad)

Performs crossover of a pair of genes

#include "amma/Num/NumFuncB.hh"

BodyRefCounterVC & Copy() const: Makes a deep copy and is virtual
As the copy constructor but is virtual so can be called from a base class reference.
void SetSizeX(UIntT X): Sets size of input vector
void SetSizeY(UIntT Y): Sets size of output vector
VectorC Apply(const VectorC & X): Evaluate Y=f(X) as a process
VectorC Evaluate(const VectorC & X) const: Evaluate Y=f(X)
This is the main function that does all the work and must be overloaded in derived classes.
DListC<VectorC> Evaluate(const DListC<VectorC> & listX) const: Evaluate Y=f(X) for a list of X
This is achieved by iterating through the list of X and using the Evaluate member function that takes a single X. For sophisticated applications where speed is important, this function can be overloaded to do batch processing.
VectorC operator()(const VectorC & X) const: Evaluate Y=f(X)
MatrixC Jacobian(const VectorC & X) const: Calculate Jacobian matrix at X
Performs numerical estimation of the Jacobian using differences. This function has and should be overloaded for all cases where the Jacobian can be calculated analytically.
const StringC GetInfo() const: Derived class information
const StringC & GetName() const: Derived class type
UIntT SizeX() const: Size of input vectors
UIntT SizeY() const: Size of output vectors
BooleanT Save(ostream & out) const: Writes object to stream, can be loaded using constructor

#include "amma/DP/Process.hh"

VectorC Apply(const VectorC &): Apply operation.
IntT ApplyArray(const SArray1dC<VectorC> & in,SArray1dC<VectorC> & out): Apply operation to an array of elements.
returns the number of elements processed.
BooleanT Save(ostream & out) const: Save to ostream.
const type_info & InputType() const: Get input type.
const type_info & OutputType() const: Get input type.
BooleanT Save(ostream & out) const: Save to ostream.
const type_info & InputType() const: Get input type.
const type_info & OutputType() const: Get input type.
ProcTypeT OpType() const: Operation type lossy/lossless.
BooleanT IsStateless() const: Is operation stateless ?

#include "amma/DP/Entity.hh"

BooleanT Save(ostream & out) const: Save to ostream.
BodyRefCounterVC & Copy() const: Creat a copy of this object.

#include "amma/BRefCntV.hh"

BodyRefCounterVC & Copy() const: Creat a copy of this object.
BooleanT operator==(const BodyRefCounterVC & oth) const: Compair identitys.
BooleanT operator!=(const BodyRefCounterVC & oth) const: Compair identitys.
BooleanT Save(ostream & out) const: Save to ostream.

#include "amma/BRefCnt.hh"

void AddReference(): Another reference to the object has been created.
void RemoveReference(): One reference to the object was deleted.
Locking scheme -------------- The object is possible to lock (to make constant). The scheme assumes that the object is created, it can be locked, after that it can only be destroyed. The locked object cannot be unlocked. This locking scheme is very useful during debugging, using assert() function, when it is necassary to check that object is treated as constant and the constancy is not violated by any casting or passing through the copy constructor of shared objects.
void SetConst(void) const: This locks the object.
Often objects you wish to lock are already const.
void SetConst(void): This locks the object.
BooleanT IsConst(void) const: Returns TRUE if the object is locked, ie. it is assumed to be constant.
BooleanT IsNotConst(void) const: Returns TRUE if the object is unlocked.
ie. there is no special information if the object is constant or not. Counter state information -------------------------
BooleanT ToBeDeleted() const: Returns TRUE if there is only one reference to the object and the whole object or its reference counting part can be deleted.
BooleanT ToBeDeletedRemoveIgnoreNoRemove(): Decrement refrence by 1 return true if this leaves no refrences to the object.
BooleanT ToBeDeletedRemove(): Decrement refrence by 1 return true if this leaves no refrences to the object. This also checks the NoRemove flag.
BooleanT BodyMightBeDeleted() const: Returns TRUE if the reference counted part of the object can be deleted, ie. flag NOREMOVE is false .
BooleanT IsCountZero() const: Are there any refrences left ?
BooleanT BRCPtrCanDeleteObject() const: Used by BRRCPtrC to establish if an object has ZERO refrences and can be deleted.
IntT Count() const: Returns the current state of the counter, ie. how many references to this object exist.
const BodyRefCounterC & operator=(const BodyRefCounterC & b): It has not meaning to assign object 'b' to this object because it would destroy a history of the object which is counted. So this is a dummy function.
BooleanT IsValidObject() const: Test if object is valid.
When amma check is disabled this always returns true.
BooleanT UserBitTest(IntT x) const: Test user flag.
void UserBitSet(IntT x,BooleanT setit = TRUE): Test user flag.
void UserBitZero(IntT x): Set bit to zero.
void ReportBRCError(char * Msg): Report error, used in BRCPtrC.
UIntT Hash() const: Hash on address of object.
void SetUndeletable(): Make object undeletable.
Usefull to prevent recursive deleting in graph structures. Only hackers need this function.
void ReportInvalidObject(char * Msg = 0) const: Tell user about validation failure.

#include "amma/RefCBase.hh"

LabelT Label() const: Returns the label of this reference counter.
The member function is useful mainly to recognize objects during debugging. The value of the label is uniquely defined pointer.

Programmer:Robert Crida, Documentation by CxxDoc: Tue Mar 20 10:49:27 2001

NumSelectGeneticBC

Implementation class for genetic algorithm feature subset selection.

include	"amma/Num/NumSelectGeneticB.hh"
User Level:	Default
Library:	NumSelect
Example:	testNumSelect.cc
Section:	Pattern Recognition.Feature Selection.Implementation
In Scope:	std