Implement un/weighted inclusive Gregory transfers

html/index.html

@@ -39,7 +39,7 @@
 				<select id="selPreset" onchange="changePreset()">
 					<option value="scottish" selected>Scottish STV</option>
 					<option value="stvc">pyRCV STV-C</option>
-					<option value="prsa77">PRSA 1977</option>
+					<option value="senate">Australian Senate STV</option>
 				</select>
 			</label>
 			<button id="btnAdvancedOptions" onclick="clickAdvancedOptions()">Show advanced options</button>
@@ -92,7 +92,7 @@
 				</select>
 			</label>
 			<label>
-				Transfer value (NYI):
+				Transfer value:
 				<select id="selTransfers">
 					<option value="wig" selected>Weighted inclusive Gregory</option>
 					<option value="uig">Unweighted inclusive Gregory</option>

html/index.js

@@ -46,7 +46,7 @@ function changePreset() {
 		document.getElementById('selSurplus').value = 'size';
 		document.getElementById('selTransfers').value = 'wig';
 		document.getElementById('selTies').value = 'backwards_random';
-	} else if (document.getElementById('selPreset').value === 'prsa77') {
+	} else if (document.getElementById('selPreset').value === 'senate') {
 		document.getElementById('selQuotaCriterion').value = 'geq';
 		document.getElementById('selQuota').value = 'droop';
 		document.getElementById('chkProgQuota').checked = false;
@@ -126,10 +126,8 @@ async function clickCount() {
 			elTd.innerText = 'Loss to fraction';
 			elLTF1.appendChild(elTd);
 			
-			if (document.getElementById('selNumbers').value === 'int') {
 			tblResults.appendChild(elLTF1);
 			tblResults.appendChild(elLTF2);
-			}
 			
 			// Total row
 			elTotal = document.createElement('tr');
@@ -170,7 +168,7 @@ async function clickCount() {
 					elTd.classList.add('elected');
 				}
 				elTd.style.borderTop = '1px solid black';
-				if (countCard.transfers != '0.00') {
+				if (countCard.transfers != '0.00' && countCard.transfers != '0') {
 					elTd.innerText = countCard.transfers;
 				}
 				elTr1.appendChild(elTd);
@@ -198,7 +196,7 @@ async function clickCount() {
 			elTd = document.createElement('td');
 			elTd.classList.add('count');
 			elTd.style.borderTop = '1px solid black';
-			if (result.exhausted.transfers != '0.00') {
+			if (result.exhausted.transfers != '0.00' && result.exhausted.transfers != '0') {
 				elTd.innerText = result.exhausted.transfers;
 			}
 			elExhausted1.appendChild(elTd);
@@ -212,14 +210,18 @@ async function clickCount() {
 			elTd = document.createElement('td');
 			elTd.classList.add('count');
 			elTd.style.borderTop = '1px solid black';
-			if (result.loss_fraction.transfers != '0.00') {
+			if (result.loss_fraction.transfers != '0.00' && result.loss_fraction.transfers != '-0.00' && result.loss_fraction.transfers != '0') {
 				elTd.innerText = result.loss_fraction.transfers;
 			}
 			elLTF1.appendChild(elTd);
 			
 			elTd = document.createElement('td');
 			elTd.classList.add('count');
+			if (result.loss_fraction.votes == '-0.00') {
+				elTd.innerText = '0.00';
+			} else {
 				elTd.innerText = result.loss_fraction.votes;
+			}
 			elLTF2.appendChild(elTd);
 			
 			// Display total
@@ -246,13 +248,13 @@ async function clickCount() {
 	worker.postMessage({
 		'numbers': document.getElementById('selNumbers').value,
 		'fixedDPs': parseInt(document.getElementById('txtDP').value),
+		'transfers': document.getElementById('selTransfers').value,
 		'options': {
 			'quota_criterion': document.getElementById('selQuotaCriterion').value,
 			'quota': document.getElementById('selQuota').value,
 			'prog_quota': document.getElementById('chkProgQuota').checked,
 			'bulk_exclude': document.getElementById('chkBulkExclusion').checked,
 			'surplus_order': document.getElementById('selSurplus').value,
-			'transfer_value': document.getElementById('selTransfers').value,
 			'ties': document.getElementById('selTies').value
 		},
 		'data': text

html/worker.js

@@ -40,7 +40,12 @@ onmessage = function(evt) {
 	}});
 	
 	// Create counter
-	let counter = py.pyRCV2.method.base_stv.BaseSTVCounter(election, evt.data.options);
+	let counter;
+	if (evt.data.transfers === 'wig') {
+		counter = py.pyRCV2.method.base_stv.BaseWIGSTVCounter(election, evt.data.options);
+	} else {
+		counter = py.pyRCV2.method.base_stv.BaseUIGSTVCounter(election, evt.data.options);
+	}
 	
 	// Reset
 	let result = counter.reset();

pyRCV2/method/base_stv.py

@@ -17,14 +17,16 @@
 __pragma__ = lambda x: None
 
 from pyRCV2.model import CandidateState, CountCard, CountCompleted, CountStepResult
-from pyRCV2.numbers import Num
+from pyRCV2.numbers import Num, Rational
 from pyRCV2.safedict import SafeDict
 
 class STVException(Exception):
 	pass
 
 class BaseSTVCounter:
-	"""Basic STV counter for various different variations"""
+	"""
+	Basic STV counter for various different variations
+	"""
 	
 	def __init__(self, election, options=None):
 		self.election = election
@@ -55,34 +57,6 @@ class BaseSTVCounter:
 			self.candidates[candidate].state = CandidateState.WITHDRAWN
 			__pragma__('noopov')
 	
-		# 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
-				self.candidates[candidate].ballots.append((ballot, ballot.value))
-			else:
-				self.exhausted.transfers += ballot.value
-				self.exhausted.ballots.append((ballot, ballot.value))
-			__pragma__('noopov')
-		
-		self.quota = None
-		self.compute_quota()
-		self.elect_meeting_quota()
-		
-		__pragma__('opov')
-		return CountStepResult(
-			'First preferences',
-			self.candidates,
-			self.exhausted,
-			self.loss_fraction,
-			self.total + self.exhausted.votes + self.loss_fraction.votes,
-			self.quota
-		)
-		__pragma__('noopov')
-	
 	def step(self):
 		# Step count cards
 		for candidate, count_card in self.candidates.items():
@@ -135,22 +109,10 @@ class BaseSTVCounter:
 			
 			__pragma__('opov')
 			surplus = count_card.votes - self.quota
-			#transfer_value = surplus / count_card.votes # Do not do this yet to avoid rounding errors
 			__pragma__('noopov')
 			
 			# Transfer surplus
-			for ballot, ballot_value in count_card.ballots:
+			self.transfer_surplus(candidate_surplus, count_card, surplus)
-				__pragma__('opov')
-				new_value = (ballot_value * surplus) / count_card.votes
-				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')
 			
 			__pragma__('opov')
 			count_card.transfers -= surplus
@@ -179,21 +141,12 @@ class BaseSTVCounter:
 		# TODO: Handle ties
 		candidate_excluded, count_card = hopefuls[0]
 		count_card.state = CandidateState.EXCLUDED
-		__pragma__('opov')
-		count_card.transfers -= count_card.votes
-		__pragma__('noopov')
 		
 		# Exclude this candidate
-		for ballot, ballot_value in count_card.ballots:
+		self.exclude_candidate(candidate_excluded, count_card)
-			__pragma__('opov')
-			candidate = next((c for c in ballot.preferences if self.candidates[c].state == CandidateState.HOPEFUL), None)
 		
-			if candidate is not None:
+		__pragma__('opov')
-				self.candidates[candidate].transfers += ballot_value
+		count_card.transfers -= count_card.votes
-				self.candidates[candidate].ballots.append((ballot, ballot_value))
-			else:
-				self.exhausted.transfers += ballot_value
-				self.exhausted.ballots.append((ballot, ballot_value))
 		__pragma__('noopov')
 		
 		# Declare any candidates meeting the quota as a result of exclusion
@@ -252,3 +205,182 @@ class BaseSTVCounter:
 				count_card.state = CandidateState.PROVISIONALLY_ELECTED
 				count_card.order_elected = self.num_elected
 				self.num_elected += 1
+
+class BaseWIGSTVCounter(BaseSTVCounter):
+	"""
+	Basic weighted inclusive Gregory STV counter
+	"""
+	
+	def reset(self):
+		BaseSTVCounter.reset(self)
+		
+		# 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
+				self.candidates[candidate].ballots.append((ballot, ballot.value))
+			else:
+				self.exhausted.transfers += ballot.value
+				self.exhausted.ballots.append((ballot, ballot.value))
+			__pragma__('noopov')
+		
+		self.quota = None
+		self.compute_quota()
+		self.elect_meeting_quota()
+		
+		__pragma__('opov')
+		return CountStepResult(
+			'First preferences',
+			self.candidates,
+			self.exhausted,
+			self.loss_fraction,
+			self.total + self.exhausted.votes + self.loss_fraction.votes,
+			self.quota
+		)
+		__pragma__('noopov')
+	
+	def transfer_surplus(self, candidate_surplus, count_card, surplus):
+		for ballot, ballot_value in count_card.ballots:
+			__pragma__('opov')
+			new_value = (ballot_value * surplus) / count_card.votes # Multiply first to avoid rounding errors
+			
+			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')
+	
+	def exclude_candidate(self, candidate_excluded, count_card):
+		for ballot, ballot_value in count_card.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
+				self.candidates[candidate].ballots.append((ballot, ballot_value))
+			else:
+				self.exhausted.transfers += ballot_value
+				self.exhausted.ballots.append((ballot, ballot_value))
+			__pragma__('noopov')
+
+class BaseUIGSTVCounter(BaseSTVCounter):
+	"""
+	Basic unweighted inclusive Gregory STV counter
+	"""
+	
+	def reset(self):
+		BaseSTVCounter.reset(self)
+		
+		# 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
+				self.candidates[candidate].ballots.append((ballot, Rational(ballot.value.pp(0))))
+			else:
+				self.exhausted.transfers += ballot.value
+				self.exhausted.ballots.append((ballot, Rational(ballot.value.pp(0))))
+			__pragma__('noopov')
+		
+		self.quota = None
+		self.compute_quota()
+		self.elect_meeting_quota()
+		
+		__pragma__('opov')
+		return CountStepResult(
+			'First preferences',
+			self.candidates,
+			self.exhausted,
+			self.loss_fraction,
+			self.total + self.exhausted.votes + self.loss_fraction.votes,
+			self.quota
+		)
+		__pragma__('noopov')
+	
+	def transfer_surplus(self, candidate_surplus, count_card, surplus):
+		# FIXME: Is it okay to use native int's here?
+		next_preferences = SafeDict([(c, []) for c, cc in self.candidates.items()])
+		next_exhausted = []
+		total_ballots = Num('0')
+		
+		# Count next preferences
+		for ballot, ballot_value in count_card.ballots:
+			__pragma__('opov')
+			total_ballots += 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].append(ballot)
+				__pragma__('noopov')
+			else:
+				next_exhausted.append(ballot)
+		
+		# 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 = (Rational(ballot.value.pp(0)) * Rational(surplus.pp(0))) / Rational(total_ballots.pp(0))
+				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 = (Rational(ballot.value.pp(0)) * Rational(surplus.pp(0))) / Rational(total_ballots.pp(0))
+			__pragma__('noopov')
+			self.exhausted.ballots.append((ballot, new_value))
+	
+	def exclude_candidate(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')
+				next_exhausted += ballot_value
+				__pragma__('noopov')
+				self.exhausted.ballots.append((ballot, ballot_value))
+		
+		# Credit votes
+		for candidate, cand_votes in next_preferences.items():
+			__pragma__('opov')
+			self.candidates[candidate].transfers += Num(cand_votes.__floor__().pp(0))
+			__pragma__('noopov')
+		
+		__pragma__('opov')
+		self.exhausted.transfers += Num(next_exhausted.__floor__().pp(0))
+		__pragma__('noopov')