def test_ell_p_norm_calculating(self):
self.assertEqual(
ell_p_norm([1], 1),
Decimal(1)
)
self.assertAlmostEquals(
ell_p_norm([1], 2),
Decimal(1)
)
self.assertAlmostEquals(
ell_p_norm([1, 2, 3], 2),
Decimal(sqrt(1 + 4 + 9))
)
self.assertAlmostEquals(
ell_p_norm([1, 2, 3], 10000),
Decimal(3)
)
def calculate_committee_score_from_prefetched(self, committee):
temp_score = 0
for voter in self.voters:
voter_preferences = []
for candidate in committee:
voter_preferences.append(
self.preferences[voter.pk][candidate.pk]
)
voter_preferences = [self.candidates_number - x for x in voter_preferences]
temp_score += voter.repeats * ell_p_norm(voter_preferences, self.p_parameter)
if temp_score > self.biggest:
self.biggest = temp_score
return temp_score
def calculate_committee_score_from_prefetched(self, committee):
temp_score = 0
for voter in self.voters:
voter_preferences = []
for candidate in committee:
voter_preferences.append(
self.preferences[voter.pk][candidate.pk])
voter_preferences = [
self.candidates_number - x for x in voter_preferences
]
temp_score += voter.repeats * ell_p_norm(voter_preferences,
self.p_parameter)
if temp_score > self.biggest:
self.biggest = temp_score
return temp_score
def calculate_committee_score(self, committee, p, candidates_number):
"""
Calculate committee score multiplied by vote repeats
:param candidates_number: number of candidates in election
:type candidates_number: int
:type committee: list of ecs.elections.models.Candidate
:type p: int
:rtype: Decimal
:return: committee score
"""
# create pos_v sequence, but order actually
# does not matter in our election system:
voter_preferences = self.preferences.filter(candidate__in=committee).values_list('preference', flat=True)
voter_preferences = [candidates_number - x for x in voter_preferences]
return self.repeats * ell_p_norm(voter_preferences, p)
def update_voters_satisfaction(self, leading_candidate, voters,
current_voters_satisfaction,
candidates_number, p):
"""
:param leading_candidate: Candidate
:param voters: QuerySet
:param current_voters_satisfaction: dict{Voter: int}
:param candidates_number: int
:param p: int
:return:
"""
for v in voters:
x = candidates_number - self.preferences[v.pk][
leading_candidate.pk]
values = [current_voters_satisfaction[v.pk], x]
current_voters_satisfaction[v.pk] = ell_p_norm(values, p)
def calculate_committee_score(self, committee, p, candidates_number):
"""
Calculate committee score multiplied by vote repeats
:param candidates_number: number of candidates in election
:type candidates_number: int
:type committee: list of ecs.elections.models.Candidate
:type p: int
:rtype: Decimal
:return: committee score
"""
# create pos_v sequence, but order actually
# does not matter in our election system:
voter_preferences = self.preferences.filter(
candidate__in=committee).values_list('preference', flat=True)
voter_preferences = [candidates_number - x for x in voter_preferences]
return self.repeats * ell_p_norm(voter_preferences, p)
def run(self):
self.fetch_preferences()
voters = list(self.election.voters.all())
candidates_still_fighting = list(self.election.candidates.all())
winning_committee = []
current_voters_satisfaction = {}
for v in voters:
current_voters_satisfaction[v.pk] = 0
for i in range(self.election.committee_size):
if settings.PRINT_PROGRESS:
print i + 1, "out of", self.election.committee_size, "to be chosen"
satisfaction_with_leading_candidate = 0
leading_candidate = None
for c in candidates_still_fighting:
satisfaction_with_given_candidate = 0
for v in voters:
x = self.candidates_number - self.preferences[v.pk][c.pk]
satisfaction_of_given_voter = current_voters_satisfaction[
v.pk]
values = [satisfaction_of_given_voter, x]
satisfaction_of_given_voter_with_given_candidate = ell_p_norm(
values, self.p_parameter)
satisfaction_with_given_candidate += v.repeats * satisfaction_of_given_voter_with_given_candidate
if satisfaction_with_given_candidate > satisfaction_with_leading_candidate:
leading_candidate = c
satisfaction_with_leading_candidate = satisfaction_with_given_candidate
self.update_voters_satisfaction(leading_candidate, voters,
current_voters_satisfaction,
self.candidates_number,
self.p_parameter)
winning_committee.append(leading_candidate)
candidates_still_fighting.remove(leading_candidate)
return tuple(winning_committee)
def test_ell_p_norm_calculating(self):
self.assertEqual(ell_p_norm([1], 1), Decimal(1))
self.assertAlmostEquals(ell_p_norm([1], 2), Decimal(1))
self.assertAlmostEquals(ell_p_norm([1, 2, 3], 2),
Decimal(sqrt(1 + 4 + 9)))
self.assertAlmostEquals(ell_p_norm([1, 2, 3], 10000), Decimal(3))