FT::Vary::Variation Class Reference

#include <variation.h>

Public Member Functions
	Variation (float cr)
	constructor More...
	Variation ()=default
void	set_cross_rate (float cr)
	update cross rate More...
float	get_cross_rate ()
	return current cross rate More...
	~Variation ()
	destructor More...
void	vary (Population &pop, const vector< size_t > &parents, const Parameters &params, const Data &d)
	method to handle variation of population More...
void	delete_mutate (Individual &child, const Parameters &params)
void	delete_dimension_mutate (Individual &child, const Parameters &params)
bool	correlation_delete_mutate (Individual &child, MatrixXf Phi, const Parameters &params, const Data &d)

Private Member Functions
bool	cross (const Individual &mom, const Individual &dad, Individual &child, const Parameters &params, const Data &d)
	crossover More...
bool	residual_cross (const Individual &mom, const Individual &dad, Individual &child, const Parameters &params, const Data &d)
	residual crossover More...
bool	stagewise_cross (const Individual &mom, const Individual &dad, Individual &child, const Parameters &params, const Data &d)
	stagewise crossover More...
bool	mutate (const Individual &mom, Individual &child, const Parameters &params, const Data &d)
	mutation More...
void	point_mutate (Individual &child, const Parameters &params)
void	insert_mutate (Individual &child, const Parameters &params)
void	splice_programs (NodeVector &vnew, const NodeVector &v1, size_t i1, size_t j1, const NodeVector &v2, size_t i2, size_t j2)
	splice two programs together More...
void	print_cross (const Individual &, size_t, size_t, const Individual &, size_t, size_t, Individual &, bool after=true)
	debugging printout of crossover operation. More...

Private Attributes
float	cross_rate
	fraction of crossover in total variation More...

Detailed Description

Definition at line 32 of file variation.h.

Constructor & Destructor Documentation

Variation() [1/2]

FT::Vary::Variation::Variation

(

float

cr

)

constructor

methods for crossover and mutation of programs.

Definition at line 11 of file variation.cc.

Variation() [2/2]

FT::Vary::Variation::Variation ( )

default

~Variation()

FT::Vary::Variation::~Variation

(

)

destructor

Definition at line 26 of file variation.cc.

Member Function Documentation

correlation_delete_mutate()

bool FT::Vary::Variation::correlation_delete_mutate	(	Individual &	child,
		MatrixXf	Phi,
		const Parameters &	params,
		const Data &	d
	)

deletion mutation. works by pruning a dimension. the dimension that is pruned matches these criteria: 1) it is in the pair of features most highly correlated. 2) it is less correlated with the dependent variable than its pair.

Parameters

child	individual to be mutated
Phi	the behavior of the parent
params	parameters
d	data

Returns

mutated child

Definition at line 465 of file variation.cc.

cross()

bool FT::Vary::Variation::cross ( const Individual &  mom, const Individual &  dad, Individual &  child, const Parameters &  params, const Data &  d  )

private

crossover

crossover by either subtree crossover or swapping of dimensions.

Parameters

mom	root parent
dad	parent from which subtree is chosen
child	result of cross
params	parameters

Returns

child: mom with dad subtree graft

Definition at line 551 of file variation.cc.

delete_dimension_mutate()

void FT::Vary::Variation::delete_dimension_mutate	(	Individual &	child,
		const Parameters &	params
	)

deletion mutation. works by pruning a dimension.

Parameters

child	individual to be mutated
params	parameters

Returns

mutated child

Definition at line 437 of file variation.cc.

delete_mutate()

void FT::Vary::Variation::delete_mutate	(	Individual &	child,
		const Parameters &	params
	)

deletion mutation. works by pruning a dimension.

Parameters

child	individual to be mutated
params	parameters

Returns

mutated child

Definition at line 359 of file variation.cc.

get_cross_rate()

float FT::Vary::Variation::get_cross_rate

(

)

return current cross rate

Definition at line 20 of file variation.cc.

insert_mutate()

void FT::Vary::Variation::insert_mutate ( Individual &  child, const Parameters &  params  )

private

insertion mutation.

Parameters

child	indiviudal to be mutated
params	parameters

Returns

modified child

Definition at line 232 of file variation.cc.

mutate()

bool FT::Vary::Variation::mutate ( const Individual &  mom, Individual &  child, const Parameters &  params, const Data &  d  )

private

mutation

chooses uniformly between point, insert and delete mutation

Parameters

mom	parent
child	offspring produced by mutating mom
params	parameters

Returns

true if valid child, false if not

Definition at line 114 of file variation.cc.

point_mutate()

void FT::Vary::Variation::point_mutate ( Individual &  child, const Parameters &  params  )

private

1/n point mutation.

Parameters

child	individual to be mutated
params	parameters

Returns

modified child

Definition at line 174 of file variation.cc.

print_cross()

void FT::Vary::Variation::print_cross ( const Individual &  mom, size_t  i1, size_t  j1, const Individual &  dad, size_t  i2, size_t  j2, Individual &  child, bool  after = true  )

private

debugging printout of crossover operation.

Definition at line 970 of file variation.cc.

residual_cross()

bool FT::Vary::Variation::residual_cross ( const Individual &  mom, const Individual &  dad, Individual &  child, const Parameters &  params, const Data &  d  )

private

residual crossover

crossover by swapping in a dimension most correlated with the residual of mom.

Parameters

mom	root parent
dad	parent from which subtree is chosen
child	result of cross
params	parameters

Returns

child: mom with dad subtree graft

Definition at line 645 of file variation.cc.

set_cross_rate()

void FT::Vary::Variation::set_cross_rate

(

float

cr

)

update cross rate

Definition at line 14 of file variation.cc.

splice_programs()

void FT::Vary::Variation::splice_programs ( NodeVector &  vnew, const NodeVector &  v1, size_t  i1, size_t  j1, const NodeVector &  v2, size_t  i2, size_t  j2  )

private

splice two programs together

swap vector subsets with different sizes. constructs a vector made of v1[0:i1], v2[i2:j2], v1[i1:end].

Parameters

v1	root parent
i1	start of splicing segment
j1	end of splicing segment
v2	donating parent
i2	start of donation
j2	end of donation

Returns

vnew: new vector

Definition at line 925 of file variation.cc.

stagewise_cross()

bool FT::Vary::Variation::stagewise_cross ( const Individual &  mom, const Individual &  dad, Individual &  child, const Parameters &  params, const Data &  d  )

private

stagewise crossover

crossover by forward stagewise selection, matching mom's dimensionality.

Parameters

mom	root parent
dad	parent from which subtree is chosen
child	result of cross
params	parameters

Returns

child: mom with dad subtree graft procedure: set the residual equal to target $y$. center means around zero for all $\phi$. set $\phi_A$ to be all subprograms in $\phi_{p0}$ and $\phi_{p1}$. while $|\phi_{c}| < |\phi_{p0}|$:

• pick $\phi^*$ from $\phi_{A}$ which is most correlated with $\mathbf{r}$.
• compute the least squares coefficient $b$ for $\phi^*$ fit to $\mathbf{r}$.
• update $\mathbf{r} = r - b\phi^*$ $\phi_c$ = all $\phi^*$ that were chosen

Definition at line 743 of file variation.cc.

vary()

void FT::Vary::Variation::vary	(	Population &	pop,
		const vector< size_t > &	parents,
		const Parameters &	params,
		const Data &	d
	)

method to handle variation of population

performs variation on the current population.

Parameters

pop	current population
parents	indices of population to use for variation
params	feat parameters

Returns

appends params.pop_size offspring derived from parent variation

Definition at line 40 of file variation.cc.

Member Data Documentation

cross_rate

float FT::Vary::Variation::cross_rate

private

fraction of crossover in total variation

Definition at line 96 of file variation.h.

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

• variation.h
• variation.cc