Module defaults

The defaults module contains the default values of all of the constants used by the Pool to create, mutate, and mate Genomes.

Constants

DEFAULT_AGE_SIGNIFICANCE

The boost that younger species (10 generations or fewer) receive to their adjusted fitness scores.

DEFAULT_CONNECTION_MUTATION_CHANCE

The likelyhood that a connection mutation will take place whenever a Genome mutates.

DEFAULT_CROSSOVER_CHANCE

The likelyhood that when a Genome is mated, that it will be mated with another Genome from another Species instead of its own.

DEFAULT_DISABLE_NODE_MUTATION_CHANCE

The likelyhood that when a Genome mutates, it will disable an existing Gene that is enabled. Note: disable mutation will only happen if neither connection mutation nor node mutation happens.

DEFAULT_DISJOINT_COEFFICIENT

Used in determining whether two Genomes are the same Species

DEFAULT_DROPOFF_AGE

The number of generations that a Species must exist without improving its fitness before it is considered stagnant, and receives an extreme penalty to its adjusted fitness score (making it much less likely to reproduce).

DEFAULT_ENABLE_NODE_MUTATION_CHANCE

The likelyhood that when a Genome mutates, it will enable an existing Gene that is disabled. Note: enable mutation will only happen if neither connection mutation nor node mutation happens.

DEFAULT_EXCESS_COEFFICIENT

Used in determining whether two Genomes are the same Species

DEFAULT_MATE_ONLY_RATE

The likelyhood that when a Genome is used as the basis for the next generation via mating, that the resulting offspring will not be mated.

DEFAULT_MUTATE_ONLY_RATE

The likelyhood that when a Genome is used as the basis for the next generation, that it will be cloned and mutated only (rather than mated).

DEFAULT_NODE_MUTATION_CHANCE

The likelyhood that a new node will be added whenever a Genome mutates. Note: node mutation will only happen if a connection mutation does not. Thus, if the connection mutation chance is set to 1.0 (100% chance), this will never happen.

DEFAULT_PERTURB_CHANCE

The likelyhood that when a Genome mutates a weight, that it will perturb it – that is to say, randomly assign it a new value between 0.0 and 1.0.

DEFAULT_POPULATION_SIZE

The default number of Genomes a Pool will maintain.

DEFAULT_SPECIES_THRESHOLD

Used in determining whether two Genomes are the same Species

DEFAULT_SURVIVAL_THRESHOLD

Used in determining how many Genomes from a Species will be used as the basis for the next generation.

DEFAULT_WEIGHT_DIFF_COEFFICIENT

Used in determining whether two Genomes are the same Species

DEFAULT_WEIGHT_MUTATION_CHANCE

The likelyhood that an existing Gene will have its weights altered whenever a Genome mutates. Note: weight mutation will only happen if neither connection mutation nor node mutation happens.

DEFAULT_WEIGHT_STEP_SIZE

The amount of change (+ or -) that a Gene’s weight will incur when a weight mutation takes place (if it has not been perturbed).