Exemple #1
0
def run_ga(n_to_test, kptdensity=None):
    ''' This method specifies how to run the GA once the
    initial random structures have been stored in godb.db.
    '''
    # Various initializations:
    population_size = 10
    da = DataConnection('godb.db')
    atom_numbers_to_optimize = da.get_atom_numbers_to_optimize()
    n_to_optimize = len(atom_numbers_to_optimize)
    slab = da.get_slab()
    all_atom_types = get_all_atom_types(slab, atom_numbers_to_optimize)
    blmin = closest_distances_generator(all_atom_types,
                                        ratio_of_covalent_radii=0.05)

    # Defining the mix of genetic operators:
    mutation_probability = 0.3333
    pairing = CutAndSplicePairing(slab, n_to_optimize, blmin)
    rattlemut = RattleMutation(blmin, n_to_optimize,
                               rattle_prop=0.8, rattle_strength=1.5)
    mirrormut = MirrorMutation(blmin, n_to_optimize)
    mutations = OperationSelector([1., 1.], [rattlemut, mirrormut])

    if True:
        # Recalculate raw scores of any relaxed candidates
        # present in the godb.db database (only applies to 
        # iter007).
        structures = da.get_all_relaxed_candidates()
        for atoms in structures:
            atoms = singlepoint(atoms)
            da.c.delete([atoms.info['relax_id']])
            if 'data' not in atoms.info:
                atoms.info['data'] = {}
            da.add_relaxed_step(atoms)
        print('Finished recalculating raw scores')

    # Relax the randomly generated initial candidates:
    while da.get_number_of_unrelaxed_candidates() > 0:
        a = da.get_an_unrelaxed_candidate()
        a.wrap()
        a = relax_one(a)
        da.add_relaxed_step(a)

    # Create the population
    population = Population(data_connection=da,
                            population_size=population_size,
                            comparator=comparator,
                            logfile='log.txt')
    current_pop = population.get_current_population()

    # Test n_to_test new candidates
    ga_raw_scores = []
    step = 0
    for step in range(n_to_test):
        print('Starting configuration number %d' % step, flush=True)

        clock = time()
        a3 = None
        r = random()
        if r > mutation_probability:
            while a3 is None:
                a1, a2 = population.get_two_candidates()
                a3, desc = pairing.get_new_individual([a1, a2])
        else:
            while a3 is None:
                a1 = population.get_one_candidate()
                a3, desc = mutations.get_new_individual([a1])

        dt = time() - clock
        op = 'pairing' if r > mutation_probability else 'mutating'
        print('Time for %s candidate(s): %.3f' % (op, dt), flush=True)

        a3.wrap()
        da.add_unrelaxed_candidate(a3, description=desc)

        a3 = relax_one(a3)
        da.add_relaxed_step(a3)

        # Various updates:
        population.update()
        current_pop = population.get_current_population()
        write('current_population.traj', current_pop)

        # Print out information for easy analysis/plotting afterwards:
        if r > mutation_probability:
            print('Step %d %s %.3f %.3f %.3f' % (step, desc,\
                   get_raw_score(a1), get_raw_score(a2), get_raw_score(a3)))
        else:
            print('Step %d %s %.3f %.3f' % (step, desc,\
                   get_raw_score(a1), get_raw_score(a3)))

        print('Step %d highest raw score in pop: %.3f' % \
              (step, get_raw_score(current_pop[0])))
        ga_raw_scores.append(get_raw_score(a3))
        print('Step %d highest raw score generated by GA: %.3f' % \
              (step, max(ga_raw_scores)))

    emin = population.pop[0].get_potential_energy()
    print('GA finished after step %d' % step)
    print('Lowest energy = %8.3f eV' % emin, flush=True)
    write('all_candidates.traj', da.get_all_relaxed_candidates())
    write('current_population.traj', population.get_current_population())
atom_numbers_to_optimize = da.get_atom_numbers_to_optimize()
n_to_optimize = len(atom_numbers_to_optimize)
slab = da.get_slab()
all_atom_types = get_all_atom_types(slab, atom_numbers_to_optimize)
blmin = closest_distances_generator(all_atom_types,
                                    ratio_of_covalent_radii=0.7)

comp = InteratomicDistanceComparator(n_top=n_to_optimize,
                                     pair_cor_cum_diff=0.015,
                                     pair_cor_max=0.7,
                                     dE=0.02,
                                     mic=False)

pairing = CutAndSplicePairing(slab, n_to_optimize, blmin)
mutations = OperationSelector([1., 1., 1.], [
    MirrorMutation(blmin, n_to_optimize),
    RattleMutation(blmin, n_to_optimize),
    PermutationMutation(n_to_optimize)
])

# Relax all unrelaxed structures (e.g. the starting population)
while da.get_number_of_unrelaxed_candidates() > 0:
    a = da.get_an_unrelaxed_candidate()
    a.set_calculator(EMT())
    print('Relaxing starting candidate {0}'.format(a.info['confid']))
    dyn = BFGS(a, trajectory=None, logfile=None)
    dyn.run(fmax=0.05, steps=100)
    a.info['key_value_pairs']['raw_score'] = -a.get_potential_energy()
    da.add_relaxed_step(a)

# create the population
Exemple #3
0
def test_basic_example_main_run(seed, testdir):
    # set up the random number generator
    rng = np.random.RandomState(seed)

    # create the surface
    slab = fcc111('Au', size=(4, 4, 1), vacuum=10.0, orthogonal=True)
    slab.set_constraint(FixAtoms(mask=len(slab) * [True]))

    # define the volume in which the adsorbed cluster is optimized
    # the volume is defined by a corner position (p0)
    # and three spanning vectors (v1, v2, v3)
    pos = slab.get_positions()
    cell = slab.get_cell()
    p0 = np.array([0., 0., max(pos[:, 2]) + 2.])
    v1 = cell[0, :] * 0.8
    v2 = cell[1, :] * 0.8
    v3 = cell[2, :]
    v3[2] = 3.

    # Define the composition of the atoms to optimize
    atom_numbers = 2 * [47] + 2 * [79]

    # define the closest distance two atoms of a given species can be to each other
    unique_atom_types = get_all_atom_types(slab, atom_numbers)
    blmin = closest_distances_generator(atom_numbers=unique_atom_types,
                                        ratio_of_covalent_radii=0.7)

    # create the starting population
    sg = StartGenerator(slab=slab,
                        blocks=atom_numbers,
                        blmin=blmin,
                        box_to_place_in=[p0, [v1, v2, v3]],
                        rng=rng)

    # generate the starting population
    population_size = 5
    starting_population = [sg.get_new_candidate() for i in range(population_size)]

    # from ase.visualize import view   # uncomment these lines
    # view(starting_population)        # to see the starting population

    # create the database to store information in
    d = PrepareDB(db_file_name=db_file,
                  simulation_cell=slab,
                  stoichiometry=atom_numbers)

    for a in starting_population:
        d.add_unrelaxed_candidate(a)

    # XXXXXXXXXX This should be the beginning of a new test,
    # but we are using some resources from the precious part.
    # Maybe refactor those things as (module-level?) fixtures.

    # Change the following three parameters to suit your needs
    population_size = 5
    mutation_probability = 0.3
    n_to_test = 5

    # Initialize the different components of the GA
    da = DataConnection('gadb.db')
    atom_numbers_to_optimize = da.get_atom_numbers_to_optimize()
    n_to_optimize = len(atom_numbers_to_optimize)
    slab = da.get_slab()
    all_atom_types = get_all_atom_types(slab, atom_numbers_to_optimize)
    blmin = closest_distances_generator(all_atom_types,
                                        ratio_of_covalent_radii=0.7)

    comp = InteratomicDistanceComparator(n_top=n_to_optimize,
                                         pair_cor_cum_diff=0.015,
                                         pair_cor_max=0.7,
                                         dE=0.02,
                                         mic=False)

    pairing = CutAndSplicePairing(slab, n_to_optimize, blmin, rng=rng)
    mutations = OperationSelector([1., 1., 1.],
                            [MirrorMutation(blmin, n_to_optimize, rng=rng),
                             RattleMutation(blmin, n_to_optimize, rng=rng),
                             PermutationMutation(n_to_optimize, rng=rng)],
                             rng=rng)

    # Relax all unrelaxed structures (e.g. the starting population)
    while da.get_number_of_unrelaxed_candidates() > 0:
        a = da.get_an_unrelaxed_candidate()
        a.calc = EMT()
        print('Relaxing starting candidate {0}'.format(a.info['confid']))
        dyn = BFGS(a, trajectory=None, logfile=None)
        dyn.run(fmax=0.05, steps=100)
        set_raw_score(a, -a.get_potential_energy())
        da.add_relaxed_step(a)

    # create the population
    population = Population(data_connection=da,
                            population_size=population_size,
                            comparator=comp,
                            rng=rng)

    # test n_to_test new candidates
    for i in range(n_to_test):
        print('Now starting configuration number {0}'.format(i))
        a1, a2 = population.get_two_candidates()
        a3, desc = pairing.get_new_individual([a1, a2])
        if a3 is None:
            continue
        da.add_unrelaxed_candidate(a3, description=desc)

        # Check if we want to do a mutation
        if rng.rand() < mutation_probability:
            a3_mut, desc = mutations.get_new_individual([a3])
            if a3_mut is not None:
                da.add_unrelaxed_step(a3_mut, desc)
                a3 = a3_mut

        # Relax the new candidate
        a3.calc = EMT()
        dyn = BFGS(a3, trajectory=None, logfile=None)
        dyn.run(fmax=0.05, steps=100)
        set_raw_score(a3, -a3.get_potential_energy())
        da.add_relaxed_step(a3)
        population.update()

    write('all_candidates.traj', da.get_all_relaxed_candidates())