1.5. Initialisation

Simple functions for performing population initialisation.

1.5.1. Custom functions

To define a custom init function, the following params are required: - adam - n - island

Example:

def initialise_population_random(adam, n : int = 10, island=None):
   population = list()

   for i in range(n - 1):
      chromosome = island.create_chromosome([x.randomise_new() for x in adam.chromosome])
      eve = island.create_individual(adam.fitness_function, chromosome=chromosome)
      population.append(eve)

   population.append(adam)

   return population

1.5.2. Initialisation

1.5.2.1. Random Initialisation

natural_selection.genetic_algorithms.operators.initialisation.initialise_population_random(adam, n: int = 10, chromosome_create_func: Optional[Callable] = None, island=None)

Classic random initialisation function to create a pool of n individuals from a starting Individual adam.

Parameters

  • adam (Individual) – An individual already initialised with a chromosome.

  • n (int) – Population size (default = 10).

  • () (chromosome_create_func) – A function to create the chromosome of new individuals. If none, simply deep copy adam’s. (default = None).

  • island (Island) – Needed to wrap to create_chromosome and create_individual methods (default = None).

Returns

Population members.

Return type

list

1.5.2.2. Initialisation with mutation function

natural_selection.genetic_algorithms.operators.initialisation.initialise_population_mutation_function(adam, n: int = 10, chromosome_create_func: Optional[Callable] = None, mutation_params: Optional[dict] = None, island=None)

Random initialisation function to create a pool of n individuals from a starting Individual adam, but uses the island.mutation function to perform the randomisation.

Parameters

  • adam (Individual) – An individual already initialised with a chromosome.

  • n (int) – Population size (default = 10).

  • () (chromosome_create_func) – A function to create the chromosome of new individuals. If none, simply deep copy adam’s. (default = None).

  • mutation_params (dict) – The params of the mutation function, these usually need to be higher values, such as higher prob value.

  • island (Island) – Needed to wrap to create_chromosome and create_individual methods (default = None).

Returns

Population members.

Return type

list

1.5.3. Alien spawn

1.5.3.1. Default spawn

natural_selection.genetic_algorithms.operators.initialisation.alien_spawn_default(island=None)

Default empty list spawning.

Parameters

island (Island) – Needed to wrap to create_chromosome and create_individual methods (default = None).

Returns

Empty

Return type

list