tra-analysis/analysis-master/tra_analysis/metrics/glicko2.py
Dev Singh 5d7ae52134 rename analysis to tra_analysis, bump version to 2.0.0
Signed-off-by: Dev Singh <dev@devksingh.com>
2020-08-10 13:28:37 -05:00

99 lines
2.5 KiB
Python

import math
class Glicko2:
_tau = 0.5
def getRating(self):
return (self.__rating * 173.7178) + 1500
def setRating(self, rating):
self.__rating = (rating - 1500) / 173.7178
rating = property(getRating, setRating)
def getRd(self):
return self.__rd * 173.7178
def setRd(self, rd):
self.__rd = rd / 173.7178
rd = property(getRd, setRd)
def __init__(self, rating = 1500, rd = 350, vol = 0.06):
self.setRating(rating)
self.setRd(rd)
self.vol = vol
def _preRatingRD(self):
self.__rd = math.sqrt(math.pow(self.__rd, 2) + math.pow(self.vol, 2))
def update_player(self, rating_list, RD_list, outcome_list):
rating_list = [(x - 1500) / 173.7178 for x in rating_list]
RD_list = [x / 173.7178 for x in RD_list]
v = self._v(rating_list, RD_list)
self.vol = self._newVol(rating_list, RD_list, outcome_list, v)
self._preRatingRD()
self.__rd = 1 / math.sqrt((1 / math.pow(self.__rd, 2)) + (1 / v))
tempSum = 0
for i in range(len(rating_list)):
tempSum += self._g(RD_list[i]) * \
(outcome_list[i] - self._E(rating_list[i], RD_list[i]))
self.__rating += math.pow(self.__rd, 2) * tempSum
def _newVol(self, rating_list, RD_list, outcome_list, v):
i = 0
delta = self._delta(rating_list, RD_list, outcome_list, v)
a = math.log(math.pow(self.vol, 2))
tau = self._tau
x0 = a
x1 = 0
while x0 != x1:
# New iteration, so x(i) becomes x(i-1)
x0 = x1
d = math.pow(self.__rating, 2) + v + math.exp(x0)
h1 = -(x0 - a) / math.pow(tau, 2) - 0.5 * math.exp(x0) \
/ d + 0.5 * math.exp(x0) * math.pow(delta / d, 2)
h2 = -1 / math.pow(tau, 2) - 0.5 * math.exp(x0) * \
(math.pow(self.__rating, 2) + v) \
/ math.pow(d, 2) + 0.5 * math.pow(delta, 2) * math.exp(x0) \
* (math.pow(self.__rating, 2) + v - math.exp(x0)) / math.pow(d, 3)
x1 = x0 - (h1 / h2)
return math.exp(x1 / 2)
def _delta(self, rating_list, RD_list, outcome_list, v):
tempSum = 0
for i in range(len(rating_list)):
tempSum += self._g(RD_list[i]) * (outcome_list[i] - self._E(rating_list[i], RD_list[i]))
return v * tempSum
def _v(self, rating_list, RD_list):
tempSum = 0
for i in range(len(rating_list)):
tempE = self._E(rating_list[i], RD_list[i])
tempSum += math.pow(self._g(RD_list[i]), 2) * tempE * (1 - tempE)
return 1 / tempSum
def _E(self, p2rating, p2RD):
return 1 / (1 + math.exp(-1 * self._g(p2RD) * \
(self.__rating - p2rating)))
def _g(self, RD):
return 1 / math.sqrt(1 + 3 * math.pow(RD, 2) / math.pow(math.pi, 2))
def did_not_compete(self):
self._preRatingRD()