From fab58ab892b6a016376fb5a636c1b0a9abd81901 Mon Sep 17 00:00:00 2001
From: RunasSudo <runassudo@yingtongli.me>
Date: Mon, 19 Oct 2020 01:40:27 +1100
Subject: [PATCH] Fix rounding errors in unweighted inclusive Gregory mode

---
 pyRCV2/method/base_stv.py     | 4 ++--
 pyRCV2/numbers/fixed_js.py    | 5 +++++
 pyRCV2/numbers/fixed_py.py    | 5 +++++
 pyRCV2/numbers/int_js.py      | 5 +++++
 pyRCV2/numbers/int_py.py      | 5 +++++
 pyRCV2/numbers/native_js.py   | 5 +++++
 pyRCV2/numbers/native_py.py   | 5 +++++
 pyRCV2/numbers/rational_js.py | 3 +++
 pyRCV2/numbers/rational_py.py | 3 +++
 9 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/pyRCV2/method/base_stv.py b/pyRCV2/method/base_stv.py
index ecb066d..6b9fcc7 100644
--- a/pyRCV2/method/base_stv.py
+++ b/pyRCV2/method/base_stv.py
@@ -416,7 +416,7 @@ class BaseUIGSTVCounter(BaseSTVCounter):
 			
 			for ballot in cand_ballots:
 				__pragma__('opov')
-				new_value = (Rational(ballot.value.pp(0)) * Rational(surplus.pp(0))) / Rational(total_ballots.pp(0))
+				new_value = (ballot.value.to_rational() * surplus.to_rational()) / total_ballots.to_rational()
 				self.candidates[candidate].ballots.append((ballot, new_value))
 				__pragma__('noopov')
 		
@@ -428,7 +428,7 @@ class BaseUIGSTVCounter(BaseSTVCounter):
 		
 		for ballot in next_exhausted:
 			__pragma__('opov')
-			new_value = (Rational(ballot.value.pp(0)) * Rational(surplus.pp(0))) / Rational(total_ballots.pp(0))
+			new_value = (ballot.value.to_rational() * surplus.to_rational()) / total_ballots.to_rational()
 			__pragma__('noopov')
 			self.exhausted.ballots.append((ballot, new_value))
 	
diff --git a/pyRCV2/numbers/fixed_js.py b/pyRCV2/numbers/fixed_js.py
index 6485797..deec595 100644
--- a/pyRCV2/numbers/fixed_js.py
+++ b/pyRCV2/numbers/fixed_js.py
@@ -31,6 +31,11 @@ class Fixed:
 		"""Pretty print to specified number of decimal places"""
 		return self.impl.toFixed(dp)
 	
+	def to_rational(self):
+		"""Convert to an instance of Rational"""
+		from pyRCV2.numbers import Rational
+		return Rational(self.impl.toString())
+	
 	def __add__(self, other):
 		return Fixed(self.impl.plus(other.impl))
 	def __sub__(self, other):
diff --git a/pyRCV2/numbers/fixed_py.py b/pyRCV2/numbers/fixed_py.py
index 7a595d5..27b4e10 100644
--- a/pyRCV2/numbers/fixed_py.py
+++ b/pyRCV2/numbers/fixed_py.py
@@ -35,6 +35,11 @@ class Fixed:
 		"""Pretty print to specified number of decimal places"""
 		return format(self.impl, '.{}f'.format(dp))
 	
+	def to_rational(self):
+		"""Convert to an instance of Rational"""
+		from pyRCV2.numbers import Rational
+		return Rational(self.impl)
+	
 	def __add__(self, other):
 		return Fixed(self.impl + other.impl)
 	def __sub__(self, other):
diff --git a/pyRCV2/numbers/int_js.py b/pyRCV2/numbers/int_js.py
index 928dae3..2571ae2 100644
--- a/pyRCV2/numbers/int_js.py
+++ b/pyRCV2/numbers/int_js.py
@@ -26,6 +26,11 @@ class NativeInt:
 		"""Pretty print to specified number of decimal places"""
 		return self.impl.toFixed(0)
 	
+	def to_rational(self):
+		"""Convert to an instance of Rational"""
+		from pyRCV2.numbers import Rational
+		return Rational(self.impl)
+	
 	def __add__(self, other):
 		return NativeInt(self.impl + other.impl)
 	def __sub__(self, other):
diff --git a/pyRCV2/numbers/int_py.py b/pyRCV2/numbers/int_py.py
index 41c7b34..ddd47c0 100644
--- a/pyRCV2/numbers/int_py.py
+++ b/pyRCV2/numbers/int_py.py
@@ -28,6 +28,11 @@ class NativeInt:
 		"""Pretty print to specified number of decimal places"""
 		return str(self.impl)
 	
+	def to_rational(self):
+		"""Convert to an instance of Rational"""
+		from pyRCV2.numbers import Rational
+		return Rational(self.impl)
+	
 	def __add__(self, other):
 		return NativeInt(self.impl + other.impl)
 	def __sub__(self, other):
diff --git a/pyRCV2/numbers/native_js.py b/pyRCV2/numbers/native_js.py
index b23afef..48489b5 100644
--- a/pyRCV2/numbers/native_js.py
+++ b/pyRCV2/numbers/native_js.py
@@ -26,6 +26,11 @@ class Native:
 		"""Pretty print to specified number of decimal places"""
 		return self.impl.toFixed(dp)
 	
+	def to_rational(self):
+		"""Convert to an instance of Rational"""
+		from pyRCV2.numbers import Rational
+		return Rational(self.impl)
+	
 	def __add__(self, other):
 		return Native(self.impl + other.impl)
 	def __sub__(self, other):
diff --git a/pyRCV2/numbers/native_py.py b/pyRCV2/numbers/native_py.py
index 702e9bf..21ac3fd 100644
--- a/pyRCV2/numbers/native_py.py
+++ b/pyRCV2/numbers/native_py.py
@@ -28,6 +28,11 @@ class Native:
 		"""Pretty print to specified number of decimal places"""
 		return format(self.impl, '.{}f'.format(dp))
 	
+	def to_rational(self):
+		"""Convert to an instance of Rational"""
+		from pyRCV2.numbers import Rational
+		return Rational(self.impl)
+	
 	def __add__(self, other):
 		return Native(self.impl + other.impl)
 	def __sub__(self, other):
diff --git a/pyRCV2/numbers/rational_js.py b/pyRCV2/numbers/rational_js.py
index cacb27a..10cc9b2 100644
--- a/pyRCV2/numbers/rational_js.py
+++ b/pyRCV2/numbers/rational_js.py
@@ -29,6 +29,9 @@ class Rational:
 		"""
 		return self.impl.valueOf().toFixed(dp)
 	
+	def to_rational(self):
+		return self
+	
 	def to_num(self):
 		"""
 		Convert to an instance of Num
diff --git a/pyRCV2/numbers/rational_py.py b/pyRCV2/numbers/rational_py.py
index 9f23c81..1e090e0 100644
--- a/pyRCV2/numbers/rational_py.py
+++ b/pyRCV2/numbers/rational_py.py
@@ -31,6 +31,9 @@ class Rational:
 		"""
 		return format(self.impl, '.{}f'.format(dp))
 	
+	def to_rational(self):
+		return self
+	
 	def to_num(self):
 		"""
 		Convert to an instance of Num