culebra.solution.parameter_optimization.Individual class

class Individual(species: Species, fitness_cls: type[Fitness], values: Sequence[int | float] | None = None)

Bases: Solution, Individual

Construct a default solution.

Parameters:

• species (Species) – The species the solution will belong to

• fitness_cls (type[Fitness]) – The solution’s fitness class

• values (Sequence[int | float]) – Initial values, optional

Raises:

• TypeError – If species is not a valid species

• TypeError – If fitness_cls is not a valid fitness class

Class attributes

Individual.eta = 5

Default value for eta, which controls the probability distribution used in SBX and polynomial mutation.

Individual.species_cls = <class 'culebra.solution.parameter_optimization.Species'>

Class for the species used by the Solution class to constrain all its instances.

Class methods

classmethod Individual.load(filename: str) → Base

Load a serialized object from a file.

Parameters:

filename (str) – The file name.

Returns:

The loaded object

Raises:

• TypeError – If filename is not a valid file name

• ValueError – If the filename extension is not SERIALIZED_FILE_EXTENSION

Properties

property Individual.fitness: Fitness

Solution’s fitness.

Return type:

Fitness

Setter:

Set a new Fitness

Parameters:

value (Fitness) – The new fitness

property Individual.named_values_cls: type[NamedTuple]

Named tuple class to hold the parameter values.

Return type:

type[NamedTuple]

property Individual.species: Species

Solution’s species.

Return type:

Species

property Individual.values: NamedTuple[int | float, ...]

Parameter values evolved by the solution.

Return type:

named_values_cls

Setter:

Set new parameter values.

Parameters:

values (Sequence[int | float]) – The new parameters values

Raises:

ValueError – If the values do not meet the species constraints

Methods

Individual.crossover(other: Individual) → tuple[Individual, Individual]

Cross this individual with another one.

SBX is used.

Parameters:

other (Individual) – The other individual

Returns:

The two offspring

Return type:

tuple[Individual]

Individual.dump(filename: str) → None

Serialize this object and save it to a file.

Parameters:

filename (str) – The file name.

Raises:

• TypeError – If filename is not a valid file name

• ValueError – If the filename extension is not SERIALIZED_FILE_EXTENSION

Individual.get(name: str) → int | float

Get the value of the parameter with the given name.

Parameters:

name (str) – Name of the parameter

Returns:

The value of the parameter

Return type:

int | float

Individual.mutate(indpb: float) → tuple[Individual]

Mutate the individual.

Polynomial mutation is used.

Parameters:

indpb (float) – Independent probability for each parameter to be mutated.

Returns:

The mutant

Return type:

tuple[Individual]

Private methods

Individual._setup() → None

Init the values of this solution randomly.

Dunder methods

Intended to compare (lexicographically) two individuals according to their fitness.

Individual.__eq__(other: Solution) → bool

Equality test.

Parameters:

other (Solution) – Other solution

Returns:

True if other codes the same solution, or False otherwise

Return type:

bool

Individual.__ge__(other: Solution) → bool

Greater than or equal to operator.

Parameters:

other (Solution) – Other solution

Returns:

True if the solution’s fitness is greater than or equal to the other’s fitness

Return type:

bool

Individual.__gt__(other: Solution) → bool

Greater than operator.

Parameters:

other (Solution) – Other solution

Returns:

True if the solution’s fitness is greater than the other’s fitness

Return type:

bool

Individual.__hash__() → int

Return the hash number for this solution.

The hash number is used for equality comparisons. Currently is implemented as the hash of the solution’s string representation.

Return type:

int

Individual.__le__(other: Solution) → bool

Less than or equal to operator.

Parameters:

other (Solution) – Other solution

Returns:

True if the solution’s fitness is less than or equal to the other’s fitness

Return type:

bool

Individual.__lt__(other: Solution) → bool

Less than operator.

Parameters:

other (Solution) – Other solution

Returns:

True if the solution’s fitness is less than the other’s fitness

Return type:

bool

Individual.__ne__(other: Solution) → bool

Not equality test.

Parameters:

other (Solution) – Other solution

Returns:

False if other codes the same solutions, or True otherwise

Return type:

bool

Individual.__str__() → str

Solution as a string.

Return type:

str