Source code for evol.helpers.mutators.permutation

from random import sample
from typing import Any, Tuple

from ..utils import select_partition

[docs]def inversion(chromosome: Tuple[Any, ...], min_size: int = 2, max_size: int = None) -> Tuple[Any, ...]: """Mutate a chromosome using inversion. Inverts a random partition of the chromosome. :param chromosome: Original chromosome. :param min_size: Minimum partition size. Defaults to 2. :param max_size: Maximum partition size. Defaults to length - 1. :return: Mutated chromosome. """ start, end = select_partition(len(chromosome), min_size, max_size) return chromosome[:start] + tuple(reversed(chromosome[start:end])) + chromosome[end:]
[docs]def swap_elements(chromosome: Tuple[Any, ...]) -> Tuple[Any, ...]: """Randomly swap two elements of the chromosome. :param chromosome: Original chromosome. :return: Mutated chromosome. """ result = list(chromosome) index_1, index_2 = sample(range(len(chromosome)), 2) result[index_1], result[index_2] = result[index_2], result[index_1] return tuple(result)