Source code for stk.ea.mutation.mutators.molecule.random_building_block

Random Building Block


import numpy as np

from ....molecule_records import MoleculeRecord
from ...records import MutationRecord
from .mutator import MoleculeMutator

[docs]class RandomBuildingBlock(MoleculeMutator): """ Substitutes random building blocks. This mutator takes a :class:`.ConstructedMolecule` and substitutes the building blocks with one chosen at random from a given set. Examples -------- *Constructed Molecule Mutation* .. testcode:: constructed-molecule-mutation import stk # Create a molecule which is to be mutated. bb1 = stk.BuildingBlock('NCCN', [stk.PrimaryAminoFactory()]) bb2 = stk.BuildingBlock('O=CCC=O', [stk.AldehydeFactory()]) polymer = stk.MoleculeRecord( topology_graph=stk.polymer.Linear((bb1, bb2), 'AB', 3), ) # Create molecules used to substitute building blocks. building_blocks = ( stk.BuildingBlock( smiles='NC[Si]CCN', functional_groups=[stk.PrimaryAminoFactory()], ), stk.BuildingBlock( smiles='NCCCCCCCN', functional_groups=[stk.PrimaryAminoFactory()], ), stk.BuildingBlock( smiles='NC1CCCCC1N', functional_groups=[stk.PrimaryAminoFactory()], ), ) # Create the mutator. def has_primary_amino_group(building_block): fg, = building_block.get_functional_groups(0) return type(fg) is stk.PrimaryAmino random_bb = stk.RandomBuildingBlock( building_blocks=building_blocks, is_replaceable=has_primary_amino_group, ) # Mutate a molecule. mutation_record1 = random_bb.mutate(polymer) # Mutate the molecule a second time. mutation_record2 = random_bb.mutate(polymer) """
[docs] def __init__( self, building_blocks, is_replaceable, name='RandomBuildingBlock', random_seed=None, ): """ Initialize a :class:`.RandomBuildingBlock` instance. Parameters ---------- building_blocks : :class:`tuple` of :class:`.BuildingBlock` A group of molecules which are used to replace building blocks in molecules being mutated. is_replaceable : :class:`callable` A function which takes a :class:`.BuildingBlock` and returns ``True`` or ``False``. This function is applied to every building block in the molecule being mutated. Building blocks which returned ``True`` are liable for substitution by one of the molecules in `building_blocks`. name : :class:`str`, optional A name to help identify the mutator instance. random_seed : :class:`int`, optional The random seed to use. """ self._building_blocks = building_blocks self._is_replaceable = is_replaceable self._name = name self._generator = np.random.RandomState(random_seed)
[docs] def mutate(self, record): # Choose the building block which undergoes mutation. replaceable_building_blocks = tuple(filter( self._is_replaceable, record.get_molecule().get_building_blocks(), )) replaced_building_block = self._generator.choice( a=replaceable_building_blocks, ) # Choose a replacement building block. replacement = self._generator.choice(self._building_blocks) # Build the new ConstructedMolecule. graph = record.get_topology_graph().with_building_blocks({ replaced_building_block: replacement, }) return MutationRecord( molecule_record=MoleculeRecord(graph), mutator_name=self._name, )