alogos.systems.whge

Weighted Hierarchical Grammatical Evolution (WHGE).

Submodules

Detailed object descriptions

alogos.systems.whge.default_parameters

Default parameters for WHGE.

These values can be changed to affect the default behavior of WHGE when used in a search algorithm. Note that the default values can also be overwritten by passing parameters to the constructor of a search algorithm.

Parameters:

  • genotype_length (int, default=1_024)

  • max_expansions (int, default=1_000_000)

  • max_depth (int, default=3)

  • init_ind_operator (str, default=”random_genotype”) – Possible values:

    • "given_genotype"

    • "random_genotype"

  • init_ind_given_genotype (Genotype, default=`None`)

  • init_pop_operator (str, default=”random_genotypes”) – Possible values:

    • "given_genotypes"

    • "random_genotypes"

  • init_pop_size (int, default=100) – This parameter is used by population initialization operators. Caution: Search methods like EvolutionaryAlgorithm come with the parameter population_size, which determines the size of the population both during initialization and during the search, therefore overwriting the value of init_pop_size.

  • init_pop_given_genotypes (list of Genotype, default=`None`)

  • init_pop_unique_genotypes (bool, default=False)

  • init_pop_unique_phenotypes (bool, default=True)

  • init_pop_unique_max_tries (int, default=100000)

  • mutation_operator (str, default=”bit_flip_by_probability”) – Possible values:

    • "bit_flip_by_probability"

    • "bit_flip_by_count"

  • mutation_bit_flip_probability (float, default=0.01)

  • mutation_bit_flip_count (int, default=2)

  • crossover_operator (str, default=”two_point_length_preserving”) – Possible values:

    • "two_point_length_preserving"

  • neighborhood_operator (str, default=”bit_flip”) – Possible values:

    • "bit_flip"

  • neighborhood_distance (int, default=1)

  • neighborhood_max_size (int, default=100)