libevocosm::fuzzy_machine< InSize, OutSize > Class Template Reference

A finite state machine. More...

#include <fuzzy_machine.h>

Inheritance diagram for libevocosm::fuzzy_machine< InSize, OutSize >:

List of all members.

Classes
struct	tranout_t
	Defines a transition and output state pair. More...

Public Member Functions
	fuzzy_machine (size_t a_size, double a_output_base, double a_output_range, double a_state_base, double a_state_range)
	Creation constructor.
	fuzzy_machine (size_t a_size)
	Creation constructor.
	fuzzy_machine (const fuzzy_machine< InSize, OutSize > &a_parent1, const fuzzy_machine< InSize, OutSize > &a_parent2)
	Construct via bisexual crossover.
	fuzzy_machine (const fuzzy_machine< InSize, OutSize > &a_source)
	Copy constructor.
virtual	~fuzzy_machine ()
	Virtual destructor.
fuzzy_machine &	operator= (const fuzzy_machine< InSize, OutSize > &a_source)
void	mutate (double a_rate)
	Mutation.
size_t	transition (size_t a_input)
	Cause state transition.
void	reset ()
	Reset to start-up state.
size_t	size () const
	Get size.
const tranout_t &	get_transition (size_t a_state, size_t a_input) const
	Get a transition from the internal state table.
size_t	num_input_states () const
	Get number of input states.
size_t	num_output_states () const
	Get number of output states.
size_t	init_state () const
	Get initial state.
size_t	current_state () const
	Get current state.
tranout_t ***	state_table ()
	Get current transition table.

Static Public Member Functions
static void	set_mutation_weight (mutation_id a_type, double a_weight)
	Set a mutation weight.

Protected Attributes
tranout_t ***	m_state_table
	State table (the machine definition)
size_t	m_size
	Number of states.
size_t	m_init_state
	Initial state.
size_t	m_current_state
	Current state.
double	m_output_base
	base value for output weights
double	m_output_range
	range for output weights
double	m_state_base
	base value for state weights
double	m_state_range
	range for state weights

Static Protected Attributes
static mutation_selector	g_selector
	Global mutation selector.

Additional Inherited Members
Static Protected Member Functions inherited from libevocosm::globals
static void	set_seed (uint32_t a_seed)
	Set the seed for the random number generator.
static uint32_t	get_seed ()
	Set the seed for the random number generator.
static std::string	version ()
	Get version number.
static size_t	rand_index (size_t n)
	Static function to allow use of g_random function pointer in random_shuffle.

---

Detailed Description

template<size_t InSize, size_t OutSize>
class libevocosm::fuzzy_machine< InSize, OutSize >

The class defines an abstract fuzzy state machine that uses integer input and output types.

A fuzzy state machine differs from a finite state machine in the selection of state transitions and outputs. In a finite state machine, each input maps to specific output and state transitions for a given current state. The fuzzy state machine contains probability maps for outputs and inputs; for any given state an input, there is a probability that any valid output could be returned, for example.

Parameters:

InSize	Number of input states
OutSize	Number of output states

---

Constructor & Destructor Documentation

template<size_t InSize, size_t OutSize>

libevocosm::fuzzy_machine< InSize, OutSize >::fuzzy_machine	(	size_t	a_size,
		double	a_output_base,
		double	a_output_range,
		double	a_state_base,
		double	a_state_range
	)

Creates a new finite state machine with a given number of states. The four weight values define the range of weights assigned to outputs and state transitions; the actual roulette tables are randomized in the range (base,base+range).

Parameters:

a_size	- Initial number of states in this machine
a_output_base	- Minimum (base) value for an output roulette wheel weight
a_output_range	- Range for an output roulette wheel weight
a_state_base	- Minimum (base) value for a new roulette wheel weight
a_state_range	- Range for a new state roulette wheel weight

References libevocosm::globals::g_random, libevocosm::prng::get_real(), libevocosm::fuzzy_machine< InSize, OutSize >::m_current_state, libevocosm::fuzzy_machine< InSize, OutSize >::m_init_state, libevocosm::fuzzy_machine< InSize, OutSize >::m_size, libevocosm::fuzzy_machine< InSize, OutSize >::m_state_table, and libevocosm::globals::rand_index().

template<size_t InSize, size_t OutSize>

libevocosm::fuzzy_machine< InSize, OutSize >::fuzzy_machine

(

size_t

a_size

)

Creates a new finite state machine with a given number of states.

Parameters:

a_size

- Initial number of states in this machine

References libevocosm::fuzzy_machine< InSize, OutSize >::m_current_state, libevocosm::fuzzy_machine< InSize, OutSize >::m_init_state, libevocosm::fuzzy_machine< InSize, OutSize >::m_size, libevocosm::fuzzy_machine< InSize, OutSize >::m_state_table, and libevocosm::globals::rand_index().

template<size_t InSize, size_t OutSize>

libevocosm::fuzzy_machine< InSize, OutSize >::fuzzy_machine	(	const fuzzy_machine< InSize, OutSize > &	a_parent1,
		const fuzzy_machine< InSize, OutSize > &	a_parent2
	)

Creates a new fuzzy_machine by combining the states of two parent machines.

Parameters:

a_parent1	- The first parent organism
a_parent2	- The second parent organism

References libevocosm::globals::g_random, libevocosm::prng::get_real(), libevocosm::fuzzy_machine< InSize, OutSize >::m_current_state, libevocosm::fuzzy_machine< InSize, OutSize >::m_init_state, libevocosm::fuzzy_machine< InSize, OutSize >::m_size, libevocosm::fuzzy_machine< InSize, OutSize >::m_state_table, and libevocosm::globals::rand_index().

template<size_t InSize, size_t OutSize>

libevocosm::fuzzy_machine< InSize, OutSize >::fuzzy_machine

(

const fuzzy_machine< InSize, OutSize > &

a_source

)

Creates a new fuzzy_machine identical to an existing one.

Parameters:

a_source

- Object to be copied

template<size_t InSize, size_t OutSize>

libevocosm::fuzzy_machine< InSize, OutSize >::~fuzzy_machine ( )

virtual

Does nothing in the base class; exists to allow destruction of derived class objects through base class (fuzzy_machine) pointers.

---

Member Function Documentation

template<size_t InSize, size_t OutSize>

size_t libevocosm::fuzzy_machine< InSize, OutSize >::current_state ( ) const

inline

Returns the current (active) state.

Returns:

The current state

template<size_t InSize, size_t OutSize>

const fuzzy_machine< InSize, OutSize >::tranout_t & libevocosm::fuzzy_machine< InSize, OutSize >::get_transition ( size_t  a_state, size_t  a_input  ) const

inline

Get a transition from the internal state table.

Parameters:

a_state	- Target state
a_input	- State information to return

Returns:

A transition from the internal state table.

template<size_t InSize, size_t OutSize>

size_t libevocosm::fuzzy_machine< InSize, OutSize >::init_state ( ) const

inline

Returns the initial (start up) state.

Returns:

The initial state

template<size_t InSize, size_t OutSize>

void libevocosm::fuzzy_machine< InSize, OutSize >::mutate

(

double

a_rate

)

Mutates a finite state machine object. The four mutations supported are:

• Change a random output symbol
• Change a random state transition
• Swap two randomly-selected states
• Randomly change the initial state Why not store the input and output sets in the machine itself? That would duplicate information across every machine of a given type, greatly increasing the memory footprint of each fuzzy_machine. The same principle holds for the mutation selector.

  Parameters:

  a_rate

  - Chance that any given state will mutate

template<size_t InSize, size_t OutSize>

size_t libevocosm::fuzzy_machine< InSize, OutSize >::num_input_states ( ) const

inline

Returns the number of input states

Returns:

The number of input states

template<size_t InSize, size_t OutSize>

size_t libevocosm::fuzzy_machine< InSize, OutSize >::num_output_states ( ) const

inline

Returns the number of output states

Returns:

The number of output states

template<size_t InSize, size_t OutSize>

fuzzy_machine< InSize, OutSize > & libevocosm::fuzzy_machine< InSize, OutSize >::operator=

(

const fuzzy_machine< InSize, OutSize > &

a_source

)

Sets an existing fuzzy_machine to duplicate another.

Parameters:

a_source

- Object to be copied

Returns:

Reference to target object

References libevocosm::fuzzy_machine< InSize, OutSize >::m_current_state, libevocosm::fuzzy_machine< InSize, OutSize >::m_init_state, libevocosm::fuzzy_machine< InSize, OutSize >::m_output_base, libevocosm::fuzzy_machine< InSize, OutSize >::m_output_range, libevocosm::fuzzy_machine< InSize, OutSize >::m_size, libevocosm::fuzzy_machine< InSize, OutSize >::m_state_base, and libevocosm::fuzzy_machine< InSize, OutSize >::m_state_range.

template<size_t InSize, size_t OutSize>

void libevocosm::fuzzy_machine< InSize, OutSize >::reset ( )

inline

Prepares the FSM to start running from its initial state.

template<size_t InSize, size_t OutSize>

void libevocosm::fuzzy_machine< InSize, OutSize >::set_mutation_weight ( mutation_id  a_type, double  a_weight  )

inlinestatic

Sets the weight value associated with a specific mutation; this changes the relative chance of this mutation happening.

Parameters:

a_type	- ID of the weight to be changed
a_weight	- New weight to be assigned

template<size_t InSize, size_t OutSize>

size_t libevocosm::fuzzy_machine< InSize, OutSize >::size ( ) const

inline

Returns the size of a fuzzy_machine.

Returns:

The size, in number of states

template<size_t InSize, size_t OutSize>

tranout_t*** libevocosm::fuzzy_machine< InSize, OutSize >::state_table ( )

inline

Returns the state transition table pointer.

This is a very dangerous function, as it gives unrestricted access to the transition table that defines a machine. Given the complexity of fuzzy state machines, I implemented this function for debugging purposes; it is not intended as a tool for directly altering the transition table. /return Pointer to the transition table for the target machine

template<size_t InSize, size_t OutSize>

size_t libevocosm::fuzzy_machine< InSize, OutSize >::transition ( size_t  a_input )

inline

Based on an input symbol, this function changes the state of an fuzzy_machine and returns an output symbol.

Parameters:

a_input

- An input symbol

Returns:

Output value resulting from transition

---

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

• fuzzy_machine.h