class IGDTermination(Termination):
def __init__(self, min_igd, pf) -> None:
super().__init__()
if pf is None:
raise Exception(
"You can only use IGD termination criteria if the pareto front is known!"
)
self.obj = IGD(pf)
self.igd = min_igd
def _do_continue(self, algorithm):
F = algorithm.pop.get("F")
return self.obj.calc(F) > self.igd
def calc(self, hyper_volume=True, delta=0.2, pf=None):
"""
This method calculates the R-IGD and R-HV based off of the population that was provided
:return: R-IGD and R-HV
"""
translated = []
final_PF = []
# 1. Prescreen Procedure - NDS Filtering
pop = self._filter()
if pf is not None:
solution = pf
else:
solution = self.problem.pareto_front()
# solution = calc_PF(1, 10000, 2)
labels = np.argmin(cdist(pop, self.ref_points), axis=1)
for i in range(len(self.ref_points)):
cluster = pop[np.where(labels == i)]
if len(cluster) != 0:
# 2. Representative Point Identification
zp = self._preprocess(cluster,
self.ref_points[i],
w_point=self.w_points[i])[0]
# 3. Filtering Procedure - Filter points
trimmed_data = self._trim(cluster, zp, range=delta)
# 4. Solution Translation
pop_t = self._translate(zp,
trimmed_data,
self.ref_points[i],
w_point=self.w_points[i])
translated.extend(pop_t)
# 5. R-Metric Computation
target = self._preprocess(data=solution,
ref_point=self.ref_points[i],
w_point=self.w_points[i])
PF = self._trim(solution, target)
final_PF.extend(PF)
translated = np.array(translated)
if np.size(translated) == 0:
igd = -1
volume = -1
else:
# IGD Computation
from pymoo.indicators.igd import IGD
IGD_ = IGD(final_PF)
igd = IGD_.calc(translated)
# HV Computation
nadir_point = np.amax(self.w_points, axis=0)
front = translated
dim = self.ref_points[0].shape[0]
if hyper_volume:
if dim < 3:
try:
# Python
from pymoo.indicators.hv import HyperVolume
hv = HyperVolume(nadir_point)
volume = hv.compute(front)
except TypeError:
volume = -1
else:
# cpp
from pymoo.cpp.hypervolume.build import hypervolume
volume = hypervolume.calculate(dim, len(front), front,
nadir_point)
else:
volume = np.nan
return igd, volume