Separate out parcel handling logic

docs/options.md

@@ -49,7 +49,7 @@ This dropdown allows you to select how numbers (vote totals, etc.) are represent
 * Native float: Numbers are represented as floating-point numbers. This is fast, but not recommended as unexpectedly large rounding errors may be introduced in some circumstances.
 * Native int: Numbers are represented as integers.
 
-Note that, when unweighted inclusive Gregory surplus transfers are used (see *Method*), ballot weights are always represented internally as fractions, while candidate totals are represented according to this option.
+Note that, during some calculations, in order to reduce rounding errors, ballot weights and intermediate may be represented internally as fractions irrespective of this option.
 
 ## Surplus order (-s/--surplus-order)
 
@@ -64,18 +64,26 @@ Some STV counting rules provide, for example, that ‘no surplus shall be transf
 
 This dropdown allows you to select how ballots are transferred during surplus transfers or exclusions. The 2 recommended methods are:
 
-* Weighted inclusive Gregory: During surplus transfers, a transfer value is calculated as the candidate's excess votes divided by the candidate's votes. Ballot weights are multiplied by the transfer value.
+* Weighted inclusive Gregory: During surplus transfers, all applicable ballot papers of the transferring candidate are examined. Transfers are weighted according to the weights of the ballot papers.
 * Wright STV: Same as weighted inclusive Gregory, but when a candidate is excluded, the count is reset from the beginning (minus the excluded candidate).
 
 Other methods are supported, but not recommended:
 
-* Unweighted inclusive Gregory: During surplus transfers, a transfer value is calculated as the candidate's excess votes divided by the candidate's ballot papers. Ballot weights are set to the transfer value.
+* Unweighted inclusive Gregory: During surplus transfers, all applicable ballot papers of the transferring candidate are examined. Transfers are not weighted, and each ballot paper has equal value in the calculation.
-* Exclusive Gregory (by parcel): During surplus transfers, only transferable papers in the ‘last bundle’ are examined. During exclusions, transfers are performed ‘parcel by parcel’, and each parcel forms a separate stage, i.e. if a parcel allows another candidate to be elected, no further transfers are made to that candidate.
+* Exclusive Gregory (last bundle): During surplus transfers, only the ballot papers received in the last transfer are examined. Transfers are not weighted.
-
-Note that, when unweighted inclusive Gregory or exclusive Gregory surplus transfers are used, ballot weights are always represented internally as fractions, while candidate totals are represented according to the *Numbers* option.
 
 Other surplus transfer methods, such as non-fractional transfers (e.g. random sample) are not supported at this time.
 
+### Papers to examine in surplus transfer (--transferable-only)
+
+* Include non-transferable papers (default): When this option is selected, all ballot papers of the transferring candidate are examined. Non-transferable papers are always exhausted at the relevant transfer values.
+* Use transferable papers only (CLI: --transferable-only): When this option is selected, only transferable papers of the transferring candidate are examined. Non-transferable papers are exhausted only if the value of the transferable papers is less than the surplus.
+
+### Exclusion method (--exclusion)
+
+* Exclude in one round (default): When excluding a candidate, transfer all their ballot papers in one round.
+* Exclude by parcel (by order): When excluding a candidate, transfer their ballot papers one parcel at a time, in their order each was received. Each parcel forms a separate round, i.e. if a transfer allows another candidate to meet the quota criterion, no further papers are transferred to that candidate.
+
 ## Ties (-t/--ties)
 
 This dropdown allows you to select how ties (in surplus transfer or exclusion) are broken. The options are:

html/index.html

@@ -105,10 +105,23 @@
 				<select id="selTransfers">
 					<option value="wig" selected>Weighted inclusive Gregory</option>
 					<option value="uig">Unweighted inclusive Gregory</option>
-					<option value="parcelled_eg">Exclusive Gregory (by parcel)</option>
+					<option value="eg">Exclusive Gregory (last bundle)</option>
 					<option value="wright">Wright STV</option>
 				</select>
 			</label>
+			<label>
+				<select id="selPapers">
+					<option value="both" selected>Include non-transferable papers</option>
+					<option value="transferable">Use transferable papers only</option>
+				</select>
+			</label>
+			<label>
+				<select id="selExclusion">
+					<option value="one_round" selected>Exclude in one round</option>
+					<option value="parcels_by_order">Exclude by parcel (by order)</option>
+					<!--<option value="parcels_by_value">Exclude by parcel (by value)</option>-->
+				</select>
+			</label>
 			<br>
 			<label>
 				Ties:

html/index.js

@@ -37,6 +37,8 @@ function changePreset() {
 		document.getElementById('txtDP').value = '5';
 		document.getElementById('selSurplus').value = 'size';
 		document.getElementById('selTransfers').value = 'wig';
+		document.getElementById('selPapers').value = 'both';
+		document.getElementById('selExclusion').value = 'one_round';
 		document.getElementById('selTies').value = 'backwards_random';
 	} else if (document.getElementById('selPreset').value === 'stvc') {
 		document.getElementById('selQuotaCriterion').value = 'gt';
@@ -47,18 +49,23 @@ function changePreset() {
 		document.getElementById('selNumbers').value = 'rational';
 		document.getElementById('selSurplus').value = 'size';
 		document.getElementById('selTransfers').value = 'wig';
+		document.getElementById('selPapers').value = 'both';
+		document.getElementById('selExclusion').value = 'one_round';
 		document.getElementById('selTies').value = 'backwards_random';
-	} /* else if (document.getElementById('selPreset').value === 'senate') {
+	} else if (document.getElementById('selPreset').value === 'senate') {
 		document.getElementById('selQuotaCriterion').value = 'geq';
 		document.getElementById('selQuota').value = 'droop';
 		document.getElementById('chkProgQuota').checked = false;
 		document.getElementById('chkBulkElection').checked = true;
 		document.getElementById('chkBulkExclusion').checked = true;
-		document.getElementById('selNumbers').value = 'int';
+		document.getElementById('selNumbers').value = 'fixed';
+		document.getElementById('txtDP').value = '0';
 		document.getElementById('selSurplus').value = 'order';
 		document.getElementById('selTransfers').value = 'uig';
+		document.getElementById('selPapers').value = 'both';
+		document.getElementById('selExclusion').value = 'parcels_by_value';
 		document.getElementById('selTies').value = 'backwards_random';
-	} */ else if (document.getElementById('selPreset').value === 'wright') {
+	} else if (document.getElementById('selPreset').value === 'wright') {
 		document.getElementById('selQuotaCriterion').value = 'geq';
 		document.getElementById('selQuota').value = 'droop';
 		document.getElementById('chkProgQuota').checked = false;
@@ -68,6 +75,8 @@ function changePreset() {
 		document.getElementById('txtDP').value = '5';
 		document.getElementById('selSurplus').value = 'size';
 		document.getElementById('selTransfers').value = 'wright';
+		document.getElementById('selPapers').value = 'both';
+		document.getElementById('selExclusion').value = 'one_round';
 		document.getElementById('selTies').value = 'backwards_random';
 	} else if (document.getElementById('selPreset').value === 'prsa77') {
 		document.getElementById('selQuotaCriterion').value = 'geq';
@@ -78,7 +87,9 @@ function changePreset() {
 		document.getElementById('selNumbers').value = 'fixed';
 		document.getElementById('txtDP').value = '0';
 		document.getElementById('selSurplus').value = 'order';
-		document.getElementById('selTransfers').value = 'parcelled_eg';
+		document.getElementById('selTransfers').value = 'eg';
+		document.getElementById('selPapers').value = 'transferable';
+		document.getElementById('selExclusion').value = 'parcels_by_order';
 		document.getElementById('selTies').value = 'backwards_random';
 	}
 }
@@ -305,6 +316,8 @@ async function clickCount() {
 				'bulk_elect': document.getElementById('chkBulkElection').checked,
 				'bulk_exclude': document.getElementById('chkBulkExclusion').checked,
 				'surplus_order': document.getElementById('selSurplus').value,
+				'papers': document.getElementById('selPapers').value,
+				'exclusion': document.getElementById('selExclusion').value,
 				'ties': document.getElementById('selTies').value
 			},
 			'seed': document.getElementById('txtSeed').value,

html/worker.js

@@ -47,8 +47,8 @@ onmessage = function(evt) {
 		// Create counter
 		if (evt.data.data.transfers === 'uig') {
 			counter = py.pyRCV2.method.base_stv.UIGSTVCounter(election, evt.data.data.options);
-		} else if (evt.data.data.transfers === 'parcelled_eg') {
+		} else if (evt.data.data.transfers === 'eg') {
-			counter = py.pyRCV2.method.parcels.ParcelledEGSTVCounter(election, evt.data.data.options);
+			counter = py.pyRCV2.method.base_stv.EGSTVCounter(election, evt.data.data.options);
 		} else if (evt.data.data.transfers === 'wright') {
 			counter = py.pyRCV2.method.wright.WrightSTVCounter(election, evt.data.data.options);
 		} else {

pyRCV2/cli/stv.py

@@ -18,8 +18,7 @@ import pyRCV2.blt
 import pyRCV2.model
 import pyRCV2.numbers
 
-from pyRCV2.method.base_stv import UIGSTVCounter, WIGSTVCounter
+from pyRCV2.method.base_stv import UIGSTVCounter, WIGSTVCounter, EGSTVCounter
-from pyRCV2.method.parcels import ParcelledEGSTVCounter
 from pyRCV2.method.wright import WrightSTVCounter
 from pyRCV2.ties import TiesBackwards, TiesPrompt, TiesRandom
 
@@ -36,7 +35,9 @@ def add_parser(subparsers):
 	parser.add_argument('--numbers', '-n', choices=['fixed', 'rational', 'int', 'native'], default='fixed', help='numbers mode (default: fixed)')
 	parser.add_argument('--decimals', type=int, default=5, help='decimal places if --numbers fixed (default: 5)')
 	parser.add_argument('--surplus-order', '-s', choices=['size', 'order'], default='size', help='whether to distribute surpluses by size or by order of election (default: size)')
-	parser.add_argument('--method', '-m', choices=['wig', 'uig', 'parcelled_eg', 'wright'], default='wig', help='method of surpluses and exclusions (default: wig - weighted inclusive Gregory)')
+	parser.add_argument('--method', '-m', choices=['wig', 'uig', 'eg', 'wright'], default='wig', help='method of surpluses and exclusions (default: wig - weighted inclusive Gregory)')
+	parser.add_argument('--transferable-only', action='store_true', help='examine only transferable papers during surplus distributions')
+	parser.add_argument('--exclusion', choices=['one_round', 'parcels_by_order', 'parcels_by_value'], default='one_round', help='whether to perform exclusions in one round or parcel by parcel (default: one_round)')
 	parser.add_argument('--ties', '-t', action='append', choices=['backwards', 'prompt', 'random'], default=None, help='how to resolve ties (default: backwards then random)')
 	parser.add_argument('--random-seed', default=None, help='arbitrary string used to seed the RNG for random tie breaking')
 
@@ -45,9 +46,9 @@ def print_step(result):
 	
 	for candidate, count_card in result.candidates.items():
 		state = None
-		if count_card.state == pyRCV2.model.CandidateState.ELECTED or count_card.state == pyRCV2.model.CandidateState.PROVISIONALLY_ELECTED:
+		if count_card.state == pyRCV2.model.CandidateState.ELECTED or count_card.state == pyRCV2.model.CandidateState.PROVISIONALLY_ELECTED or count_card.state == pyRCV2.model.CandidateState.DISTRIBUTING_SURPLUS:
 			state = 'ELECTED'
-		elif count_card.state == pyRCV2.model.CandidateState.EXCLUDED:
+		elif count_card.state == pyRCV2.model.CandidateState.EXCLUDED or count_card.state == pyRCV2.model.CandidateState.EXCLUDING:
 			state = 'Excluded'
 		elif count_card.state == pyRCV2.model.CandidateState.WITHDRAWN:
 			state = 'Withdrawn'
@@ -82,8 +83,8 @@ def main(args):
 	# Create counter
 	if args.method == 'uig':
 		counter = UIGSTVCounter(election, vars(args))
-	elif args.method == 'parcelled_eg':
+	elif args.method == 'eg':
-		counter = ParcelledEGSTVCounter(election, vars(args))
+		counter = EGSTVCounter(election, vars(args))
 	elif args.method == 'wright':
 		counter = WrightSTVCounter(election, vars(args))
 	else:
@@ -105,6 +106,7 @@ def main(args):
 			counter.options['ties'].append(TiesRandom(args.random_seed))
 	
 	counter.options['bulk_elect'] = not args.no_bulk_election
+	counter.options['papers'] = 'transferable' if args.transferable_only else 'both'
 	
 	# Reset
 	result = counter.reset()

pyRCV2/method/base_stv.py

@@ -40,6 +40,8 @@ class BaseSTVCounter:
 			'quota': 'droop',         # 'droop', 'droop_exact', 'hare' or 'hare_exact'
 			'quota_criterion': 'geq', # 'geq' or 'gt'
 			'surplus_order': 'size',  # 'size' or 'order'
+			'papers': 'both',         # 'both' or 'transferable'
+			'exclusion': 'one_round', # 'one_round', 'parcels_by_order' or 'parcels_by_value'
 			'ties': []
 		}
 		
@@ -98,10 +100,13 @@ class BaseSTVCounter:
 			
 			if candidate is not None:
 				self.candidates[candidate].transfers += ballot.value
-				self.candidates[candidate].ballots.append((ballot, self.cls_ballot_value(ballot.value)))
+				if len(self.candidates[candidate].parcels) == 0:
+					self.candidates[candidate].parcels.append([(ballot, self.cls_ballot_value(ballot.value))])
+				else:
+					self.candidates[candidate].parcels[0].append((ballot, self.cls_ballot_value(ballot.value)))
 			else:
 				self.exhausted.transfers += ballot.value
-				self.exhausted.ballots.append((ballot, self.cls_ballot_value(ballot.value)))
+				#self.exhausted.parcels[0].append((ballot, self.cls_ballot_value(ballot.value)))
 			__pragma__('noopov')
 	
 	def step(self):
@@ -211,14 +216,7 @@ class BaseSTVCounter:
 			__pragma__('noopov')
 			
 			# Transfer surplus
-			is_complete = self.do_surplus(candidate_surplus, count_card, surplus)
+			self.do_surplus(candidate_surplus, count_card, surplus)
-			
-			if is_complete:
-				__pragma__('opov')
-				count_card.transfers -= surplus
-				__pragma__('noopov')
-				
-				count_card.state = CandidateState.ELECTED
 			
 			# Declare elected any candidates meeting the quota as a result of surpluses
 			self.compute_quota()
@@ -246,6 +244,39 @@ class BaseSTVCounter:
 		"""
 		raise NotImplementedError('Method not implemented')
 	
+	def next_preferences(self, parcels):
+		"""
+		Examine the specified parcels and group ballot papers by next available preference
+		"""
+		# SafeDict: Candidate -> [List[Ballot], ballots, votes]
+		next_preferences = SafeDict([(c, [[], Num('0'), Rational('0')]) for c, cc in self.candidates.items()])
+		total_ballots = Num('0')
+		total_votes = Rational('0')
+		
+		next_exhausted = []
+		exhausted_ballots = Num('0')
+		exhausted_votes = Rational('0')
+		
+		for parcel in parcels:
+			for ballot, ballot_value in parcel:
+				__pragma__('opov')
+				total_ballots += ballot.value
+				total_votes += ballot_value.to_rational()
+				candidate = next((c for c in ballot.preferences if self.candidates[c].state == CandidateState.HOPEFUL), None)
+				
+				if candidate is not None:
+					next_preferences[candidate][0].append((ballot, ballot_value))
+					next_preferences[candidate][1] += ballot.value
+					next_preferences[candidate][2] += ballot_value.to_rational()
+				else:
+					next_exhausted.append((ballot, ballot_value))
+					exhausted_ballots += ballot.value
+					exhausted_votes += ballot_value.to_rational()
+				
+				__pragma__('noopov')
+		
+		return next_preferences, total_ballots, total_votes, next_exhausted, exhausted_ballots, exhausted_votes
+	
 	def before_exclusion(self):
 		"""
 		Check before excluding a candidate
@@ -286,7 +317,7 @@ class BaseSTVCounter:
 		count_card.state = CandidateState.EXCLUDING
 		
 		# Exclude this candidate
-		is_complete = self.do_exclusion(candidate_excluded, count_card)
+		self.do_exclusion(candidate_excluded, count_card)
 		
 		# Declare any candidates meeting the quota as a result of exclusion
 		self.compute_quota()
@@ -445,133 +476,237 @@ class WIGSTVCounter(BaseSTVCounter):
 	"""
 	
 	def do_surplus(self, candidate_surplus, count_card, surplus):
-		for ballot, ballot_value in count_card.ballots:
+		next_preferences, total_ballots, total_votes, next_exhausted, exhausted_ballots, exhausted_votes = self.next_preferences(count_card.parcels)
+		
+		if self.options['papers'] == 'transferable':
 			__pragma__('opov')
-			new_value = (ballot_value * surplus) / count_card.votes # Multiply first to avoid rounding errors
+			transferable_votes = total_votes.to_num() - exhausted_votes.to_num()
-			
-			candidate = next((c for c in ballot.preferences if self.candidates[c].state == CandidateState.HOPEFUL), None)
-			
-			if candidate is not None:
-				self.candidates[candidate].transfers += new_value
-				self.candidates[candidate].ballots.append((ballot, new_value))
-			else:
-				self.exhausted.transfers += new_value
-				self.exhausted.ballots.append((ballot, new_value))
 			__pragma__('noopov')
 		
-		return True
+		for candidate, x in next_preferences.items():
+			cand_ballots = x[0]
+			num_ballots = x[1]
+			num_votes = x[2]
+			
+			new_parcel = []
+			if len(cand_ballots) > 0:
+				__pragma__('opov')
+				self.candidates[candidate].parcels.append(new_parcel)
+				__pragma__('noopov')
+			
+			__pragma__('opov')
+			if self.options['papers'] == 'transferable':
+				if transferable_votes > surplus:
+					self.candidates[candidate].transfers += (num_votes.to_num() * surplus) / transferable_votes
+				else:
+					self.candidates[candidate].transfers += num_votes.to_num() # Do not allow weight to increase
+			else:
+				self.candidates[candidate].transfers += (num_votes.to_num() * surplus) / total_votes.to_num()
+			__pragma__('noopov')
+			
+			for ballot, ballot_value in cand_ballots:
+				__pragma__('opov')
+				if self.options['papers'] == 'transferable':
+					if transferable_votes > surplus:
+						new_value = (ballot_value * surplus) / transferable_votes
+					else:
+						new_value = ballot_value
+				else:
+					new_value = (ballot_value * surplus) / total_votes.to_num()
+				
+				new_parcel.append((ballot, new_value))
+				__pragma__('noopov')
+		
+		__pragma__('opov')
+		if self.options['papers'] == 'transferable':
+			if transferable_votes > surplus:
+				pass # No ballots exhaust
+			else:
+				self.exhausted.transfers += (surplus - transferable_votes)
+		else:
+			self.exhausted.transfers += (exhausted_votes.to_num() * surplus) / total_votes.to_num()
+		__pragma__('noopov')
+		
+		__pragma__('opov')
+		count_card.transfers -= surplus
+		__pragma__('noopov')
+		
+		count_card.state = CandidateState.ELECTED
 	
 	def do_exclusion(self, candidate_excluded, count_card):
-		for ballot, ballot_value in count_card.ballots:
+		if self.options['exclusion'] == 'parcels_by_order':
-			__pragma__('opov')
+			parcel = count_card.parcels[0]
-			candidate = next((c for c in ballot.preferences if self.candidates[c].state == CandidateState.HOPEFUL), None)
+			next_preferences, total_ballots, total_votes, next_exhausted, exhausted_ballots, exhausted_votes = self.next_preferences([parcel])
+			count_card.parcels.remove(parcel)
+		elif self.options['exclusion'] == 'parcels_by_value':
+			raise Exception('Not implemented')
+		else: # one_round
+			next_preferences, total_ballots, total_votes, next_exhausted, exhausted_ballots, exhausted_votes = self.next_preferences(count_card.parcels)
+			count_card.parcels = []
 		
-			if candidate is not None:
+		for candidate, x in next_preferences.items():
-				self.candidates[candidate].transfers += ballot_value
+			cand_ballots = x[0]
-				self.candidates[candidate].ballots.append((ballot, ballot_value))
+			num_ballots = x[1]
-			else:
+			num_votes = x[2]
-				self.exhausted.transfers += ballot_value
+			
-				self.exhausted.ballots.append((ballot, ballot_value))
+			new_parcel = []
+			if len(cand_ballots) > 0:
+				__pragma__('opov')
+				self.candidates[candidate].parcels.append(new_parcel)
 				__pragma__('noopov')
 			
 			__pragma__('opov')
-		count_card.transfers -= count_card.votes
+			self.candidates[candidate].transfers += num_votes.to_num()
 			__pragma__('noopov')
 			
+			for ballot, ballot_value in cand_ballots:
+				__pragma__('opov')
+				new_parcel.append((ballot, ballot_value))
+				__pragma__('noopov')
+		
+		__pragma__('opov')
+		self.exhausted.transfers += exhausted_votes.to_num()
+		__pragma__('noopov')
+		
+		__pragma__('opov')
+		count_card.transfers -= total_votes.to_num()
+		__pragma__('noopov')
+		
+		if len(count_card.parcels) == 0:
 			count_card.state = CandidateState.EXCLUDED
 
-class UIGSTVCounter(BaseSTVCounter):
+class UIGSTVCounter(WIGSTVCounter):
 	"""
 	Basic unweighted inclusive Gregory STV counter
 	"""
 	
 	def __init__(self, *args):
-		BaseSTVCounter.__init__(self, *args)
+		WIGSTVCounter.__init__(self, *args)
 		# Need to use Rational for ballot value internally, as Num may be set to integers only
-		#self.cls_ballot_value = Rational
 		self.cls_ballot_value = lambda x: x.to_rational()
 	
 	def do_surplus(self, candidate_surplus, count_card, surplus):
-		# FIXME: Is it okay to use native int's here?
+		next_preferences, total_ballots, total_votes, next_exhausted, exhausted_ballots, exhausted_votes = self.next_preferences(count_card.parcels)
-		next_preferences = SafeDict([(c, []) for c, cc in self.candidates.items()])
-		next_exhausted = []
-		total_ballots = Num('0')
 		
-		# Count next preferences
+		if self.options['papers'] == 'transferable':
-		for ballot, ballot_value in count_card.ballots:
 			__pragma__('opov')
-			total_ballots += ballot.value
+			transferable_ballots = total_ballots - exhausted_ballots
-			candidate = next((c for c in ballot.preferences if self.candidates[c].state == CandidateState.HOPEFUL), None)
+			transferable_votes = total_votes.to_num() - exhausted_votes.to_num()
 			__pragma__('noopov')
 		
-			if candidate is not None:
+		for candidate, x in next_preferences.items():
+			cand_ballots = x[0]
+			num_ballots = x[1]
+			num_votes = x[2]
+			
+			new_parcel = []
+			if len(cand_ballots) > 0:
 				__pragma__('opov')
-				next_preferences[candidate].append(ballot)
+				self.candidates[candidate].parcels.append(new_parcel)
 				__pragma__('noopov')
+			
+			__pragma__('opov')
+			if self.options['papers'] == 'transferable':
+				if transferable_votes > surplus:
+					self.candidates[candidate].transfers += (num_ballots * surplus) / transferable_ballots
 				else:
-				next_exhausted.append(ballot)
+					self.candidates[candidate].transfers += num_votes.to_num()
-		
-		# Make transfers
-		for candidate, cand_ballots in next_preferences.items():
-			num_ballots = sum((b.value for b in cand_ballots), Num('0'))
-			
-			__pragma__('opov')
-			self.candidates[candidate].transfers += (num_ballots * surplus) / total_ballots # Multiply first to avoid rounding errors
-			__pragma__('noopov')
-			
-			for ballot in cand_ballots:
-				__pragma__('opov')
-				new_value = (ballot.value.to_rational() * surplus.to_rational()) / total_ballots.to_rational()
-				self.candidates[candidate].ballots.append((ballot, new_value))
-				__pragma__('noopov')
-		
-		num_exhausted = sum((b.value for b in next_exhausted), Num('0'))
-		
-		__pragma__('opov')
-		self.exhausted.transfers += (num_exhausted * surplus) / total_ballots
-		__pragma__('noopov')
-		
-		for ballot in next_exhausted:
-			__pragma__('opov')
-			new_value = (ballot.value.to_rational() * surplus.to_rational()) / total_ballots.to_rational()
-			__pragma__('noopov')
-			self.exhausted.ballots.append((ballot, new_value))
-		
-		return True
-	
-	def do_exclusion(self, candidate_excluded, count_card):
-		next_preferences = SafeDict([(c, Rational('0')) for c, cc in self.candidates.items()])
-		next_exhausted = Rational('0')
-		total_votes = Rational('0')
-		
-		# Count and transfer next preferences
-		for ballot, ballot_value in count_card.ballots:
-			__pragma__('opov')
-			total_votes += ballot_value
-			candidate = next((c for c in ballot.preferences if self.candidates[c].state == CandidateState.HOPEFUL), None)
-			__pragma__('noopov')
-			
-			if candidate is not None:
-				__pragma__('opov')
-				next_preferences[candidate] += ballot_value
-				self.candidates[candidate].ballots.append((ballot, ballot_value))
-				__pragma__('noopov')
 			else:
-				__pragma__('opov')
+				self.candidates[candidate].transfers += (num_ballots * surplus) / total_ballots
-				next_exhausted += ballot_value
 			__pragma__('noopov')
-				self.exhausted.ballots.append((ballot, ballot_value))
 			
-		# Credit votes
+			for ballot, ballot_value in cand_ballots:
-		for candidate, cand_votes in next_preferences.items():
 				__pragma__('opov')
-			self.candidates[candidate].transfers += cand_votes.to_num()
+				if self.options['papers'] == 'transferable':
+					if transferable_votes > surplus:
+						new_value = (ballot.value * surplus) / transferable_ballots
+					else:
+						new_value = ballot_value
+				else:
+					new_value = (ballot.value * surplus) / total_ballots
+				
+				new_parcel.append((ballot, new_value))
 				__pragma__('noopov')
 		
 		__pragma__('opov')
-		self.exhausted.transfers += next_exhausted.to_num()
+		if self.options['papers'] == 'transferable':
-		
+			if transferable_votes > surplus:
-		count_card.transfers -= count_card.votes
+				pass # No ballots exhaust
+			else:
+				self.exhausted.transfers += (surplus - transferable_votes)
+		else:
+			self.exhausted.transfers += (exhausted_ballots * surplus) / total_ballots
 		__pragma__('noopov')
 		
-		count_card.state = CandidateState.EXCLUDED
+		__pragma__('opov')
+		count_card.transfers -= surplus
+		__pragma__('noopov')
+		
+		count_card.state = CandidateState.ELECTED
+
+class EGSTVCounter(UIGSTVCounter):
+	"""
+	Exclusive Gregory (last bundle) STV implementation
+	"""
+	
+	def do_surplus(self, candidate_surplus, count_card, surplus):
+		"""Overrides UIGSTVCounter.do_surplus"""
+		
+		last_bundle = count_card.parcels[len(count_card.parcels)-1]
+		next_preferences, total_ballots, total_votes, next_exhausted, exhausted_ballots, exhausted_votes = self.next_preferences([last_bundle])
+		
+		if self.options['papers'] == 'transferable':
+			__pragma__('opov')
+			transferable_ballots = total_ballots - exhausted_ballots
+			transferable_votes = total_votes.to_num() - exhausted_votes.to_num()
+			__pragma__('noopov')
+		
+		for candidate, x in next_preferences.items():
+			cand_ballots = x[0]
+			num_ballots = x[1]
+			num_votes = x[2]
+			
+			new_parcel = []
+			if len(cand_ballots) > 0:
+				__pragma__('opov')
+				self.candidates[candidate].parcels.append(new_parcel)
+				__pragma__('noopov')
+			
+			__pragma__('opov')
+			if self.options['papers'] == 'transferable':
+				if transferable_votes > surplus:
+					self.candidates[candidate].transfers += (num_ballots * surplus) / transferable_ballots
+				else:
+					self.candidates[candidate].transfers += num_votes.to_num()
+			else:
+				self.candidates[candidate].transfers += (num_ballots * surplus) / total_ballots
+			__pragma__('noopov')
+			
+			for ballot, ballot_value in cand_ballots:
+				__pragma__('opov')
+				if self.options['papers'] == 'transferable':
+					if transferable_votes > surplus:
+						new_value = (ballot.value * surplus) / transferable_ballots
+					else:
+						new_value = ballot_value
+				else:
+					new_value = (ballot.value * surplus) / total_ballots
+				
+				new_parcel.append((ballot, new_value))
+				__pragma__('noopov')
+		
+		__pragma__('opov')
+		if self.options['papers'] == 'transferable':
+			if transferable_votes > surplus:
+				pass # No ballots exhaust
+			else:
+				self.exhausted.transfers += (surplus - transferable_votes)
+		else:
+			self.exhausted.transfers += (exhausted_ballots * surplus) / total_ballots
+		__pragma__('noopov')
+		
+		__pragma__('opov')
+		count_card.transfers -= surplus
+		__pragma__('noopov')
+		
+		count_card.state = CandidateState.ELECTED

pyRCV2/method/parcels.py

@@ -1,177 +0,0 @@
-#   pyRCV2: Preferential vote counting
-#   Copyright © 2020  Lee Yingtong Li (RunasSudo)
-#
-#   This program is free software: you can redistribute it and/or modify
-#   it under the terms of the GNU Affero General Public License as published by
-#   the Free Software Foundation, either version 3 of the License, or
-#   (at your option) any later version.
-#
-#   This program is distributed in the hope that it will be useful,
-#   but WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-#   GNU Affero General Public License for more details.
-#
-#   You should have received a copy of the GNU Affero General Public License
-#   along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
-__pragma__ = lambda x: None
-
-from pyRCV2.method.base_stv import UIGSTVCounter
-from pyRCV2.model import CandidateState, CountCard
-from pyRCV2.numbers import Num, Rational
-from pyRCV2.safedict import SafeDict
-
-class ParcelledEGCountCard(CountCard):
-	def __init__(self, *args):
-		CountCard.__init__(self, *args)
-		del self.ballots
-		self.parcels = []
-	
-	#@property
-	#def ballots(self):
-	#	raise Exception('Attempted to access ballots attribute of ParcelledUIGCountCard')
-	
-	def clone(self):
-		"""Overrides CountCard.clone"""
-		result = ParcelledUIGCountCard()
-		result.orig_votes = self.orig_votes
-		result.transfers = self.transfers
-		result.parcels = [[(b[0].clone(), b[1]) for b in p] for p in self.parcels]
-		result.state = self.state
-		result.order_elected = self.order_elected
-		return result
-
-class ParcelledEGSTVCounter(UIGSTVCounter):
-	"""
-	Exclusive Gregory (parcel by parcel) STV implementation
-	"""
-	
-	def __init__(self, *args):
-		UIGSTVCounter.__init__(self, *args)
-		self.candidates = SafeDict([(c, ParcelledEGCountCard()) for c in self.election.candidates])
-	
-	def distribute_first_preferences(self):
-		"""Overrides UIGSTVCounter.distribute_first_preferences"""
-		
-		for ballot in self.election.ballots:
-			__pragma__('opov')
-			candidate = next((c for c in ballot.preferences if self.candidates[c].state == CandidateState.HOPEFUL), None)
-			
-			if candidate is not None:
-				self.candidates[candidate].transfers += ballot.value
-				if len(self.candidates[candidate].parcels) == 0:
-					self.candidates[candidate].parcels.append([(ballot, self.cls_ballot_value(ballot.value))])
-				else:
-					self.candidates[candidate].parcels[0].append((ballot, self.cls_ballot_value(ballot.value)))
-			else:
-				self.exhausted.transfers += ballot.value
-				self.exhausted.ballots.append((ballot, self.cls_ballot_value(ballot.value)))
-			__pragma__('noopov')
-	
-	def do_surplus(self, candidate_surplus, count_card, surplus):
-		"""Overrides UIGSTVCounter.do_surplus"""
-		
-		next_preferences = SafeDict([(c, []) for c, cc in self.candidates.items()])
-		total_ballots = Num('0')
-		total_votes = Rational('0')
-		
-		parcel = count_card.parcels[len(count_card.parcels)-1] # Last bundle only
-		
-		__pragma__('opov')
-		
-		# Count next preferences
-		for ballot, ballot_value in parcel:
-			candidate = next((c for c in ballot.preferences if self.candidates[c].state == CandidateState.HOPEFUL), None)
-			
-			if candidate is not None:
-				# Examine only transferable ballot papers
-				total_ballots += ballot.value
-				total_votes += ballot_value
-				next_preferences[candidate].append((ballot, ballot_value))
-		
-		# Make transfers
-		for candidate, cand_ballots in next_preferences.items():
-			if len(cand_ballots) == 0:
-				continue
-			
-			new_parcel = []
-			self.candidates[candidate].parcels.append(new_parcel)
-			
-			if total_votes.to_num() > surplus:
-				# Reweight according to transfer value
-				num_ballots = sum((b.value for b, bv in cand_ballots), Num('0'))
-				self.candidates[candidate].transfers += (num_ballots * surplus) / total_ballots # Multiply first to avoid rounding errors
-				
-				for ballot, ballot_value in cand_ballots:
-					new_value = (ballot.value.to_rational() * surplus.to_rational()) / total_ballots.to_rational()
-					new_parcel.append((ballot, new_value))
-			else:
-				# Do not reweight
-				num_votes = sum((bv for b, bv in cand_ballots), Rational('0'))
-				self.candidates[candidate].transfers += num_votes.to_num()
-				
-				for ballot, ballot_value in cand_ballots:
-					new_parcel.append((ballot, ballot_value))
-		
-		# Credit exhausted votes (only if not reweighting)
-		if total_votes.to_num() <= surplus:
-			self.exhausted.transfers += surplus - total_votes.to_num()
-		
-		__pragma__('noopov')
-		
-		return True
-	
-	def do_exclusion(self, candidate_excluded, count_card):
-		"""Overrides UIGSTVCounter.do_exclusion"""
-		
-		next_preferences = SafeDict([(c, []) for c, cc in self.candidates.items()])
-		next_exhausted = []
-		
-		if len(count_card.parcels) > 0:
-			parcel = count_card.parcels[0]
-			count_card.parcels.remove(parcel)
-			
-			# Count next preferences
-			for ballot, ballot_value in parcel:
-				__pragma__('opov')
-				candidate = next((c for c in ballot.preferences if self.candidates[c].state == CandidateState.HOPEFUL), None)
-				__pragma__('noopov')
-				
-				if candidate is not None:
-					__pragma__('opov')
-					next_preferences[candidate].append((ballot, ballot_value))
-					__pragma__('noopov')
-				else:
-					next_exhausted.append((ballot, ballot_value))
-			
-			# Make transfers
-			for candidate, cand_ballots in next_preferences.items():
-				if len(cand_ballots) == 0:
-					continue
-				
-				new_parcel = []
-				__pragma__('opov')
-				self.candidates[candidate].parcels.append(new_parcel)
-				__pragma__('noopov')
-				
-				num_votes = sum((bv for b, bv in cand_ballots), Rational('0'))
-				__pragma__('opov')
-				self.candidates[candidate].transfers += num_votes.to_num()
-				count_card.transfers -= num_votes.to_num()
-				__pragma__('noopov')
-				
-				for ballot, ballot_value in cand_ballots:
-					new_parcel.append((ballot, ballot_value))
-			
-			# Credit exhausted votes
-			num_votes = sum((bv for b, bv in next_exhausted), Rational('0'))
-			__pragma__('opov')
-			self.exhausted.transfers += num_votes.to_num()
-			count_card.transfers -= num_votes.to_num()
-			__pragma__('noopov')
-			
-			for ballot, ballot_value in next_exhausted:
-				self.exhausted.ballots.append((ballot, ballot_value))
-		
-		if len(count_card.parcels) == 0:
-			count_card.state = CandidateState.EXCLUDED

pyRCV2/model.py

@@ -64,10 +64,14 @@ class CountCard:
 	def __init__(self):
 		self.orig_votes = Num('0')
 		self.transfers = Num('0')
-		self.ballots = []
 		self.state = CandidateState.HOPEFUL
 		self.order_elected = None
 		
+		# self.parcels = List[Parcel]
+		# Parcel = List[Tuple[Ballot, Num]]
+		# The exhausted/loss to fraction piles will have only one parcel
+		self.parcels = []
+	
 	@property
 	def votes(self):
 		__pragma__('opov')
@@ -84,7 +88,7 @@ class CountCard:
 		result = CountCard()
 		result.orig_votes = self.orig_votes
 		result.transfers = self.transfers
-		result.ballots = [(b[0].clone(), b[1]) for b in self.ballots]
+		result.parcels = [[(b[0].clone(), b[1]) for b in p] for p in self.parcels]
 		result.state = self.state
 		result.order_elected = self.order_elected
 		return result

pyRCV2/transcrypt.py

@@ -16,7 +16,7 @@
 
 import pyRCV2.blt
 import pyRCV2.model
-import pyRCV2.method, pyRCV2.method.base_stv, pyRCV2.method.parcels, pyRCV2.method.wright
+import pyRCV2.method, pyRCV2.method.base_stv, pyRCV2.method.wright
 import pyRCV2.numbers
 import pyRCV2.random
 import pyRCV2.ties