]> de.git.xonotic.org Git - xonotic/xonstat.git/blobdiff - xonstat/elo.py
Get rid of joined_pretty_date in favor of the mixin.
[xonotic/xonstat.git] / xonstat / elo.py
old mode 100755 (executable)
new mode 100644 (file)
index 4ba3553..01a1e8a
-import sys\r
-import math\r
-import random\r
-\r
-class EloParms:\r
-    def __init__(self, global_K = 15, initial = 100, floor = 100, logdistancefactor = math.log(10)/float(400), maxlogdistance = math.log(10)):\r
-        self.global_K = global_K\r
-        self.initial = initial\r
-        self.floor = floor\r
-        self.logdistancefactor = logdistancefactor\r
-        self.maxlogdistance = maxlogdistance\r
-\r
-\r
-class KReduction:\r
-    def __init__(self, fulltime, mintime, minratio, games_min, games_max, games_factor):\r
-        self.fulltime = fulltime\r
-        self.mintime = mintime\r
-        self.minratio = minratio\r
-        self.games_min = games_min\r
-        self.games_max = games_max\r
-        self.games_factor = games_factor\r
-\r
-    def eval(self, mygames, mytime, matchtime):\r
-        if mytime < self.mintime:\r
-            return 0\r
-        if mytime < self.minratio * matchtime:\r
-            return 0\r
-        if mytime < self.fulltime:\r
-            k = mytime / float(self.fulltime)\r
-        else:\r
-            k = 1.0\r
-        if mygames >= self.games_max:\r
-            k *= self.games_factor\r
-        elif mygames > self.games_min:\r
-            k *= 1.0 - (1.0 - self.games_factor) * (mygames - self.games_min) / float(self.games_max - self.games_min)\r
-        return k\r
-\r
-\r
-# For team games where multiple scores and elos are at play, the elos\r
-# must be adjusted according to their strength relative to the player\r
-# in the next-lowest scoreboard position.\r
-def update(elos, ep):\r
-    for x in elos:\r
-        if x.elo == None:\r
-            x.elo = ep.initial\r
-        x.eloadjust = 0\r
-    if len(elos) < 2:\r
-        return elos\r
-    for i in xrange(0, len(elos)):\r
-        ei = elos[i]\r
-        for j in xrange(i+1, len(elos)):\r
-            ej = elos[j]\r
-            si = ei.score\r
-            sj = ej.score\r
-\r
-            # normalize scores\r
-            ofs = min(0, si, sj)\r
-            si -= ofs\r
-            sj -= ofs\r
-            if si + sj == 0:\r
-                si, sj = 1, 1 # a draw\r
-\r
-            # real score factor\r
-            scorefactor_real = si / float(si + sj)\r
-\r
-            # estimated score factor by elo\r
-            elodiff = min(ep.maxlogdistance, max(-ep.maxlogdistance, (ei.elo - ej.elo) * ep.logdistancefactor))\r
-            scorefactor_elo = 1 / (1 + math.exp(-elodiff))\r
-\r
-            # how much adjustment is good?\r
-            # scorefactor(elodiff) = 1 / (1 + e^(-elodiff * logdistancefactor))\r
-            # elodiff(scorefactor) = -ln(1/scorefactor - 1) / logdistancefactor\r
-            # elodiff'(scorefactor) = 1 / ((scorefactor) (1 - scorefactor) logdistancefactor)\r
-            # elodiff'(scorefactor) >= 4 / logdistancefactor\r
-\r
-            # adjust'(scorefactor) = K1 + K2\r
-\r
-            # so we want:\r
-            # K1 + K2 <= 4 / logdistancefactor <= elodiff'(scorefactor)\r
-            # as we then don't overcompensate\r
-\r
-            adjustment = scorefactor_real - scorefactor_elo\r
-            ei.eloadjust += adjustment\r
-            ej.eloadjust -= adjustment\r
-    for x in elos:\r
-        x.elo = max(x.elo + x.eloadjust * x.k * ep.global_K / float(len(elos) - 1), ep.floor)\r
-        x.games += 1\r
-    return elos\r
-\r
-\r
-# parameters for K reduction\r
-# this may be touched even if the DB already exists\r
-KREDUCTION = KReduction(600, 120, 0.5, 0, 32, 0.2)\r
-\r
-# parameters for chess elo\r
-# only global_K may be touched even if the DB already exists\r
-# we start at K=200, and fall to K=40 over the first 20 games\r
-ELOPARMS = EloParms(global_K = 200)\r
-\r
+import datetime
+import logging
+import math
+
+from xonstat.models import PlayerElo
+
+log = logging.getLogger(__name__)
+
+
+class EloParms:
+    def __init__(self, global_K = 15, initial = 100, floor = 100, logdistancefactor = math.log(10)/float(400), maxlogdistance = math.log(10)):
+        self.global_K = global_K
+        self.initial = initial
+        self.floor = floor
+        self.logdistancefactor = logdistancefactor
+        self.maxlogdistance = maxlogdistance
+
+
+class KReduction:
+    def __init__(self, fulltime, mintime, minratio, games_min, games_max, games_factor):
+        self.fulltime = fulltime
+        self.mintime = mintime
+        self.minratio = minratio
+        self.games_min = games_min
+        self.games_max = games_max
+        self.games_factor = games_factor
+
+    def eval(self, mygames, mytime, matchtime):
+        if mytime < self.mintime:
+            return 0
+        if mytime < self.minratio * matchtime:
+            return 0
+        if mytime < self.fulltime:
+            k = mytime / float(self.fulltime)
+        else:
+            k = 1.0
+        if mygames >= self.games_max:
+            k *= self.games_factor
+        elif mygames > self.games_min:
+            k *= 1.0 - (1.0 - self.games_factor) * (mygames - self.games_min) / float(self.games_max - self.games_min)
+        return k
+
+
+class EloWIP:
+    """EloWIP is a work-in-progress Elo value. It contains all of the
+    attributes necessary to calculate Elo deltas for a given game."""
+    def __init__(self, player_id, pgstat=None):
+        # player_id this belongs to
+        self.player_id = player_id
+
+        # score per second in the game
+        self.score_per_second = 0.0
+
+        # seconds alive during a given game
+        self.alivetime = 0
+
+        # current elo record
+        self.elo = None
+
+        # current player_game_stat record
+        self.pgstat = pgstat
+
+        # Elo algorithm K-factor 
+        self.k = 0.0
+
+        # Elo points accumulator, which is not adjusted by the K-factor
+        self.adjustment = 0.0
+
+        # elo points delta accumulator for the game, which IS adjusted 
+        # by the K-factor
+        self.elo_delta = 0.0
+
+    def should_save(self):
+        """Determines if the elo and pgstat attributes of this instance should
+        be persisted to the database"""
+        return self.k > 0.0
+
+    def __repr__(self):
+        return "<EloWIP(player_id={}, score_per_second={}, alivetime={}, \
+                elo={}, pgstat={}, k={}, adjustment={}, elo_delta={})>".\
+                format(self.player_id, self.score_per_second, self.alivetime, \
+                self.elo, self.pgstat, self.k, self.adjustment, self.elo_delta)
+
+
+class EloProcessor:
+    """EloProcessor is a container for holding all of the intermediary AND
+    final values used to calculate Elo deltas for all players in a given
+    game."""
+    def __init__(self, session, game, pgstats):
+
+        # game which we are processing
+        self.game = game
+
+        # work-in-progress values, indexed by player
+        self.wip = {}
+
+        # used to determine if a pgstat record is elo-eligible
+        def elo_eligible(pgs):
+            return pgs.player_id > 2 and pgs.alivetime > timedelta(seconds=0)
+
+        # only process elos for elo-eligible players
+        for pgstat in filter(elo_eligible, pgstats):
+            self.wip[pgstat.player_id] = EloWIP(pgstat.player_id, pgstat)
+
+        # determine duration from the maximum alivetime
+        # of the players if the game doesn't have one
+        self.duration = 0
+        if game.duration is not None:
+            self.duration = game.duration.seconds
+        else:
+            self.duration = max(i.alivetime.seconds for i in elostats)
+
+        # Calculate the score_per_second and alivetime values for each player.
+        # Warmups may mess up the player alivetime values, so this is a 
+        # failsafe to put the alivetime ceiling to be the game's duration.
+        for e in self.wip.values():
+            if e.pgstat.alivetime.seconds > self.duration:
+                e.score_per_second = e.pgstat.score/float(self.duration)
+                e.alivetime = self.duration
+            else:
+                e.score_per_second = e.pgstat.score/float(e.pgstat.alivetime.seconds)
+                e.alivetime = e.pgstat.alivetime.seconds
+
+        # Fetch current Elo values for all players. For players that don't yet 
+        # have an Elo record, we'll give them a default one.
+        for e in session.query(PlayerElo).\
+                filter(PlayerElo.player_id.in_(self.wip.keys())).\
+                filter(PlayerElo.game_type_cd==game.game_type_cd).all():
+                    self.wip[e.player_id].elo = e
+
+        for pid in self.wip.keys():
+            if self.wip[pid].elo is None:
+                self.wip[pid].elo = PlayerElo(pid, game.game_type_cd, ELOPARMS.initial)
+
+            # determine k reduction
+            self.wip[pid].k = KREDUCTION.eval(self.wip[pid].elo.games, 
+                    self.wip[pid].alivetime, self.duration)
+
+        # we don't process the players who have a zero K factor
+        self.wip = { e.player_id:e for e in self.wip.values() if e.k > 0.0}
+
+        # now actually process elos
+        self.process()
+
+        # DEBUG
+        # for w in self.wip.values():
+            # log.debug(w.player_id)
+            # log.debug(w)
+
+    def scorefactor(self, si, sj):
+        """Calculate the real scorefactor of the game. This is how players
+        actually performed, which is compared to their expected performance as
+        predicted by their Elo values."""
+        scorefactor_real = si / float(si + sj)
+
+        # duels are done traditionally - a win nets
+        # full points, not the score factor
+        if self.game.game_type_cd == 'duel':
+            # player i won
+            if scorefactor_real > 0.5:
+                scorefactor_real = 1.0
+            # player j won
+            elif scorefactor_real < 0.5:
+                scorefactor_real = 0.0
+            # nothing to do here for draws
+
+        return scorefactor_real
+
+    def process(self):
+        """Perform the core Elo calculation, storing the values in the "wip"
+        dict for passing upstream."""
+        if len(self.wip.keys()) < 2:
+            return
+
+        ep = ELOPARMS
+
+        pids = self.wip.keys()
+        for i in xrange(0, len(pids)):
+            ei = self.wip[pids[i]].elo
+            for j in xrange(i+1, len(pids)):
+                ej = self.wip[pids[j]].elo
+                si = self.wip[pids[i]].score_per_second
+                sj = self.wip[pids[j]].score_per_second
+
+                # normalize scores
+                ofs = min(0, si, sj)
+                si -= ofs
+                sj -= ofs
+                if si + sj == 0:
+                    si, sj = 1, 1 # a draw
+
+                # real score factor
+                scorefactor_real = self.scorefactor(si, sj)
+
+                # expected score factor by elo
+                elodiff = min(ep.maxlogdistance, max(-ep.maxlogdistance,
+                    (float(ei.elo) - float(ej.elo)) * ep.logdistancefactor))
+                scorefactor_elo = 1 / (1 + math.exp(-elodiff))
+
+                # initial adjustment values, which we may modify with additional rules
+                adjustmenti = scorefactor_real - scorefactor_elo
+                adjustmentj = scorefactor_elo - scorefactor_real
+
+                # DEBUG
+                # log.debug("(New) Player i: {0}".format(ei.player_id))
+                # log.debug("(New) Player i's K: {0}".format(self.wip[pids[i]].k))
+                # log.debug("(New) Player j: {0}".format(ej.player_id))
+                # log.debug("(New) Player j's K: {0}".format(self.wip[pids[j]].k))
+                # log.debug("(New) Scorefactor real: {0}".format(scorefactor_real))
+                # log.debug("(New) Scorefactor elo: {0}".format(scorefactor_elo))
+                # log.debug("(New) adjustment i: {0}".format(adjustmenti))
+                # log.debug("(New) adjustment j: {0}".format(adjustmentj))
+
+                if scorefactor_elo > 0.5:
+                # player i is expected to win
+                    if scorefactor_real > 0.5:
+                    # he DID win, so he should never lose points.
+                        adjustmenti = max(0, adjustmenti)
+                    else:
+                    # he lost, but let's make it continuous (making him lose less points in the result)
+                        adjustmenti = (2 * scorefactor_real - 1) * scorefactor_elo
+                else:
+                # player j is expected to win
+                    if scorefactor_real > 0.5:
+                    # he lost, but let's make it continuous (making him lose less points in the result)
+                        adjustmentj = (1 - 2 * scorefactor_real) * (1 - scorefactor_elo)
+                    else:
+                    # he DID win, so he should never lose points.
+                        adjustmentj = max(0, adjustmentj)
+
+                self.wip[pids[i]].adjustment += adjustmenti
+                self.wip[pids[j]].adjustment += adjustmentj
+
+        for pid in pids:
+            w = self.wip[pid]
+            old_elo = float(w.elo.elo)
+            new_elo = max(float(w.elo.elo) + w.adjustment * w.k * ep.global_K / float(len(pids) - 1), ep.floor)
+            w.elo_delta = new_elo - old_elo
+
+            w.elo.elo = new_elo
+            w.elo.games += 1
+            w.elo.update_dt = datetime.datetime.utcnow()
+
+            # log.debug("Setting Player {0}'s Elo delta to {1}. Elo is now {2}\
+                    # (was {3}).".format(pid, w.elo_delta, new_elo, old_elo))
+
+    def save(self, session):
+        """Put all changed PlayerElo and PlayerGameStat instances into the
+        session to be updated or inserted upon commit."""
+        # first, save all of the player_elo values
+        for w in self.wip.values():
+            session.add(w.elo)
+
+            try:
+                w.pgstat.elo_delta = w.elo_delta
+                session.add(w.pgstat)
+            except:
+                log.debug("Unable to save Elo delta value for player_id {0}".format(w.player_id))
+
+
+# parameters for K reduction
+# this may be touched even if the DB already exists
+KREDUCTION = KReduction(600, 120, 0.5, 0, 32, 0.2)
+
+# parameters for chess elo
+# only global_K may be touched even if the DB already exists
+# we start at K=200, and fall to K=40 over the first 20 games
+ELOPARMS = EloParms(global_K = 200)