def binary_tournament(pop, P, algorithm):
if P.shape[1] != 2:
raise ValueError("Only implemented for binary tournament!")
tournament_type = algorithm.tournament_type
S = np.full(P.shape[0], np.nan)
for i in range(P.shape[0]):
a, b = P[i, 0], P[i, 1]
if tournament_type == 'comp_by_dom_and_crowding':
rel = Dominator.get_relation(pop[a].F, pop[b].F)
if rel == 1:
S[i] = a
elif rel == -1:
S[i] = b
elif tournament_type == 'comp_by_rank_and_crowding':
S[i] = compare(a,
pop[a].rank,
b,
pop[b].rank,
method='smaller_is_better')
else:
raise Exception("Unknown tournament type.")
if np.isnan(S[i]):
S[i] = compare(a,
pop[a].get("crowding"),
b,
pop[b].get("crowding"),
method='larger_is_better',
return_random_if_equal=True)
return S[:, None].astype(np.int)
def update_PCpop(pc_pop, off):
pc_objs = pc_pop.get("F")
off_objs = off.get("F")
n = pc_objs.shape[0]
del_ind = []
for i in range(n):
flag = Dominator.get_relation(off_objs[0, :], pc_objs[i, :])
if flag == 1:
# off dominates pc_pop[i]
del_ind.append(i)
break
elif flag == -1:
# pc_pop[i] dominates off
return pc_pop
else:
# flag == 0
# off and pc_pop[i] are nondominated
break
if len(del_ind) > 0:
pc_index = np.arange(n)
# Delete element at index positions given by the list 'del_ind'
pc_index = np.delete(pc_index, del_ind)
pc_pop = pc_pop[pc_index.tolist()]
pc_pop = Population.merge(pc_pop, off)
return pc_pop
def sequential_search(F, i, fronts) -> int:
"""
Find the front rank for the i-th individual through sequential search
Parameters
----------
F: np.ndarray
the objective values
i: int
the index of the individual
fronts: list
individuals in each front
"""
num_found_fronts = len(fronts)
k = 0 # the front now checked
current = F[i]
while True:
if num_found_fronts == 0:
return 0
# solutions in the k-th front, examine in reverse order
fk_indices = fronts[k]
solutions = F[fk_indices[::-1]]
non_dominated = True
for f in solutions:
relation = Dominator.get_relation(current, f)
if relation == -1:
non_dominated = False
break
if non_dominated:
return k
else:
k += 1
if k >= num_found_fronts:
# move the individual to a new front
return num_found_fronts
def naive_non_dominated_sort(F, **kwargs):
M = Dominator.calc_domination_matrix(F)
fronts = []
remaining = set(range(M.shape[0]))
while len(remaining) > 0:
front = []
for i in remaining:
is_dominated = False
dominating = set()
for j in front:
rel = M[i, j]
if rel == 1:
dominating.add(j)
elif rel == -1:
is_dominated = True
break
if is_dominated:
continue
else:
front = [x for x in front if x not in dominating]
front.append(i)
[remaining.remove(e) for e in front]
fronts.append(front)
return fronts
def comp_by_dom_and_crowding(pop, P, crowding, **kwargs):
if P.shape[1] != 2:
raise ValueError("Only implemented for binary tournament!")
S = np.zeros((P.shape[0], 1), dtype=np.int)
for i, p in enumerate(P):
rel = Dominator.get_relation(pop.F[P[i, 0], :], pop.F[P[i, 1], :])
# first by domination
if rel == 1:
S[i, 0] = P[i, 0]
elif rel == -1:
S[i, 0] = P[i, 1]
# then by crowding
else:
if crowding[P[i, 0]] > crowding[P[i, 1]]:
S[i, 0] = P[i, 0]
elif crowding[P[i, 1]] > crowding[P[i, 0]]:
S[i, 0] = P[i, 1]
else:
S[i, 0] = P[i, random.randint(0, 2)]
return S
def binary_tournament(pop, P, algorithm, **kwargs):
n_tournaments, n_parents = P.shape
if n_parents != 2:
raise ValueError("Only implemented for binary tournament!")
tournament_type = algorithm.tournament_type
S = np.full(n_tournaments, np.nan)
for i in range(n_tournaments):
a, b = P[i, 0], P[i, 1]
a_cv, a_f, b_cv, b_f, = pop[a].CV[0], pop[a].F, pop[b].CV[0], pop[b].F
rank_a, cd_a = pop[a].get("rank", "crowding")
rank_b, cd_b = pop[b].get("rank", "crowding")
# if at least one solution is infeasible
if a_cv > 0.0 or b_cv > 0.0:
S[i] = compare(a,
a_cv,
b,
b_cv,
method='smaller_is_better',
return_random_if_equal=True)
# both solutions are feasible
else:
if tournament_type == 'comp_by_dom_and_crowding':
rel = Dominator.get_relation(a_f, b_f)
if rel == 1:
S[i] = a
elif rel == -1:
S[i] = b
elif tournament_type == 'comp_by_rank_and_crowding':
S[i] = compare(a,
rank_a,
b,
rank_b,
method='smaller_is_better')
else:
raise Exception("Unknown tournament type.")
# if rank or domination relation didn't make a decision compare by crowding
if np.isnan(S[i]):
S[i] = compare(a,
cd_a,
b,
cd_b,
method='larger_is_better',
return_random_if_equal=True)
return S[:, None].astype(int, copy=False)
def binary_tournament(pop, P, algorithm, **kwargs):
if P.shape[1] != 2:
raise ValueError("Only implemented for binary tournament!")
tournament_type = algorithm.tournament_type
S = np.full(P.shape[0], np.nan)
for i in range(P.shape[0]):
a, b = P[i, 0], P[i, 1]
# if at least one solution is infeasible
if pop[a].CV > 0.0 or pop[b].CV > 0.0:
S[i] = compare(
a,
pop[a].CV,
b,
pop[b].CV,
method="smaller_is_better",
return_random_if_equal=True,
)
# both solutions are feasible
else:
if tournament_type == "comp_by_dom_and_crowding":
rel = Dominator.get_relation(pop[a].F, pop[b].F)
if rel == 1:
S[i] = a
elif rel == -1:
S[i] = b
elif tournament_type == "comp_by_rank_and_crowding":
S[i] = compare(
a, pop[a].rank, b, pop[b].rank, method="smaller_is_better"
)
else:
raise Exception("Unknown tournament type.")
# if rank or domination relation didn't make a decision compare by crowding
if np.isnan(S[i]):
S[i] = compare(
a,
pop[a].get("crowding"),
b,
pop[b].get("crowding"),
method="larger_is_better",
return_random_if_equal=True,
)
return S[:, None].astype(np.int)
def binary_search(F, i, fronts):
"""
Find the front rank for the i-th individual through binary search.
Parameters
----------
F: np.ndarray
the objective values
i: int
the index of the individual
fronts: list
individuals in each front
"""
num_found_fronts = len(fronts)
if num_found_fronts == 0:
return 0
k_min = 0 # the lower bound for checking
k_max = num_found_fronts # the upper bound for checking
k = floor((k_max + k_min) / 2 + 0.5) # the front now checked
current = F[i]
while True:
# solutions in the k-th front, examine in reverse order
fk_indices = fronts[k - 1]
solutions = F[fk_indices[::-1]]
non_dominated = True
for f in solutions:
relation = Dominator.get_relation(current, f)
if relation == -1:
non_dominated = False
break
# binary search
if non_dominated:
if k == k_min + 1:
return k - 1
else:
k_max = k
k = floor((k_max + k_min) / 2 + 0.5)
else:
k_min = k
if k_max == k_min + 1 and k_max < num_found_fronts:
return k_max - 1
elif k_min == num_found_fronts:
return num_found_fronts
else:
k = floor((k_max + k_min) / 2 + 0.5)
def comp_by_dom_and_crowding(pop, indices, data):
if len(indices) != 2:
raise ValueError("Only implemented for binary tournament!")
first = indices[0]
second = indices[1]
rel = Dominator.get_relation(pop.F[first, :], pop.F[second, :])
if rel == 1:
return first
elif rel == -1:
return second
else:
if data.crowding[first] > data.crowding[second]:
return first
elif data.crowding[second] > data.crowding[first]:
return second
else:
return indices[random.randint(0, 2)]
def comp_by_cv_dom_then_random(pop, P, **kwargs):
S = np.full(P.shape[0], np.nan)
for i in range(P.shape[0]):
a, b = P[i, 0], P[i, 1]
if pop[a].CV <= 0.0 and pop[b].CV <= 0.0:
rel = Dominator.get_relation(pop[a].F, pop[b].F)
if rel == 1:
S[i] = a
elif rel == -1:
S[i] = b
else:
S[i] = np.random.choice([a, b])
elif pop[a].CV <= 0.0:
S[i] = a
elif pop[b].CV <= 0.0:
S[i] = b
else:
S[i] = np.random.choice([a, b])
return S[:, None].astype(np.int)
def find_non_dominated(F, _F=None):
M = Dominator.calc_domination_matrix(F, _F)
I = np.where(np.all(M >= 0, axis=1))[0]
return I
def fast_non_dominated_sort(F, **kwargs):
M = Dominator.calc_domination_matrix(F)
# calculate the dominance matrix
n = M.shape[0]
fronts = []
if n == 0:
return fronts
# final rank that will be returned
n_ranked = 0
ranked = np.zeros(n, dtype=int)
# for each individual a list of all individuals that are dominated by this one
is_dominating = [[] for _ in range(n)]
# storage for the number of solutions dominated this one
n_dominated = np.zeros(n)
current_front = []
for i in range(n):
for j in range(i + 1, n):
rel = M[i, j]
if rel == 1:
is_dominating[i].append(j)
n_dominated[j] += 1
elif rel == -1:
is_dominating[j].append(i)
n_dominated[i] += 1
if n_dominated[i] == 0:
current_front.append(i)
ranked[i] = 1.0
n_ranked += 1
# append the first front to the current front
fronts.append(current_front)
# while not all solutions are assigned to a pareto front
while n_ranked < n:
next_front = []
# for each individual in the current front
for i in current_front:
# all solutions that are dominated by this individuals
for j in is_dominating[i]:
n_dominated[j] -= 1
if n_dominated[j] == 0:
next_front.append(j)
ranked[j] = 1.0
n_ranked += 1
fronts.append(next_front)
current_front = next_front
return fronts
def train(self, x, f, cross_val=False, *args, **kwargs):
# f = (f - np.min(f))/(np.max(f)-np.min(f))
f_normalized = self.normalize.normalize(f, self.dataset_func)
kf = KFold(n_splits=self.n_splits)
best_acc = 0
best_loss = np.inf
if self.dataset_func is False:
cv = np.copy(f_normalized)
index = np.any(f_normalized > 0, axis=1)
cv[f_normalized <= 0] = 0
cv = np.sum(cv, axis=1)
acv = np.sum(f_normalized, axis=1)
acv[index] = np.copy(cv[index])
g_label = cv > 0
g_label[cv <= 0] = -1
# g_label = g > 0
# g_label[g <= 0] = -1
g_label = g_label.astype(int)
g_label = np.vstack(g_label)
# cross-validation
for train_index, test_index in kf.split(x):
train_data_x, test_data_x, train_data_f, test_data_f \
= x[train_index], x[test_index], f_normalized[train_index], f_normalized[test_index]
if self.dataset_func:
self.train_dominance_matrix = Dominator.calc_domination_matrix(
f_normalized[train_index])
self.test_dominance_matrix = Dominator.calc_domination_matrix(
f_normalized[test_index])
else:
train_data_cv, test_data_cv, train_g_label, test_g_label, \
= torch.from_numpy(cv[train_index]), torch.from_numpy(cv[test_index]), \
torch.from_numpy(g_label[train_index]), torch.from_numpy(g_label[test_index])
train_data_x, test_data_x, train_data_f, test_data_f \
= torch.from_numpy(train_data_x), torch.from_numpy(test_data_x), torch.from_numpy(train_data_f), \
torch.from_numpy(test_data_f)
train_indices = torch.from_numpy(
np.asarray(range(0, train_data_x.shape[0])))
test_indices = torch.from_numpy(
np.asarray(range(0, test_data_x.shape[0])))
if self.dataset_func:
self.trainset = DatasetFunction(train_indices, train_data_x,
train_data_f)
self.testset = DatasetFunction(test_indices, test_data_x,
test_data_f)
else:
self.trainset = DatasetConstraint(train_indices, train_data_x,
train_data_f, train_g_label)
self.testset = DatasetConstraint(test_indices, test_data_x,
test_data_f, test_g_label)
self.trainloader = torch.utils.data.DataLoader(
self.trainset, batch_size=self.batch_size, shuffle=True)
self.testloader = torch.utils.data.DataLoader(
self.testset, batch_size=self.batch_size, shuffle=True)
self.net = copy.deepcopy(self.neuralnet)
self.optimizer = optim.Adam(self.net.parameters(),
lr=0.01,
weight_decay=5e-1,
betas=(0.9, 0.999))
self.scheduler = CosineAnnealingLR(self.optimizer,
T_max=self.total_epoch,
eta_min=1e-7)
model, acc, loss = self.train_partition()
if self.best_accuracy_model:
if acc > best_acc:
self.model = model
else:
if loss < best_loss:
self.model = model
if not self.cross_val:
break
return self.model
def calc_as_fronts(F, G=None, only_pareto_front=False):
"""
try:
import pygmo as pg
ndf, dl, dc, ndr = pg.fast_non_dominated_sorting(F)
except ImportError:
pass
"""
# calculate the dominance matrix
n = F.shape[0]
M = Dominator.calc_domination_matrix(F, G)
fronts = []
# final rank that will be returned
n_ranked = 0
ranked = np.zeros(n, dtype=np.int)
# for each individual a list of all individuals that are dominated by this one
is_dominating = [[] for _ in range(n)]
# storage for the number of solutions dominated this one
n_dominated = np.zeros(n)
current_front = []
for i in range(n):
for j in range(i + 1, n):
rel = M[i, j]
if rel == 1:
is_dominating[i].append(j)
n_dominated[j] += 1
elif rel == -1:
is_dominating[j].append(i)
n_dominated[i] += 1
if n_dominated[i] == 0:
current_front.append(i)
ranked[i] = 1.0
n_ranked += 1
if only_pareto_front:
return current_front
# append the first front to the current front
fronts.append(current_front)
# while not all solutions are assigned to a pareto front
while n_ranked < n:
next_front = []
# for each individual in the current front
for i in current_front:
# all solutions that are dominated by this individuals
for j in is_dominating[i]:
n_dominated[j] -= 1
if n_dominated[j] == 0:
next_front.append(j)
ranked[j] = 1.0
n_ranked += 1
fronts.append(next_front)
current_front = next_front
return fronts
