File size: 7,893 Bytes
fe56a4f
 
 
 
cb658f7
 
fe56a4f
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
cb658f7
fe56a4f
 
 
 
 
cb658f7
fe56a4f
cb658f7
fe56a4f
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
cb658f7
 
fe56a4f
 
 
 
 
 
 
 
 
 
 
 
 
cb658f7
fe56a4f
 
 
 
cb658f7
fe56a4f
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
from collections import deque
from Arena import Arena
from MCTS import MCTS
import numpy as np
from progress.bar import Bar
from quoridor.pytorch.NNet import AverageMeter
import time, os, sys
from pickle import Pickler, Unpickler
from random import shuffle


class Coach():
    """
    This class executes the self-play + learning. It uses the functions defined
    in Game and NeuralNet. args are specified in main.py.
    """
    def __init__(self, game, nnet, args):
        self.game = game
        self.nnet = nnet
        self.pnet = self.nnet.__class__(self.game)  # the competitor network
        self.args = args
        self.mcts = MCTS(self.game, self.nnet, self.args)
        self.trainExamplesHistory = []    # history of examples from args.numItersForTrainExamplesHistory latest iterations
        self.skipFirstSelfPlay = False # can be overriden in loadTrainExamples()

    def executeEpisode(self):
        """
        This function executes one episode of self-play, starting with player 1.
        As the game is played, each turn is added as a training example to
        trainExamples. The game is played till the game ends. After the game
        ends, the outcome of the game is used to assign values to each example
        in trainExamples.

        It uses a temp=1 if episodeStep < tempThreshold, and thereafter
        uses temp=0.

        Returns:
            trainExamples: a list of examples of the form (canonicalBoard,pi,v)
                           pi is the MCTS informed policy vector, v is +1 if
                           the player eventually won the game, else -1.
        """
        trainExamples = []
        board = self.game.getInitBoard()
        self.curPlayer = 1
        episodeStep = 0
        while True and episodeStep<200:
            episodeStep += 1
            canonicalBoard = self.game.getCanonicalForm(board,self.curPlayer)
            valids = self.game.getValidMoves(canonicalBoard, 1)
            temp = int(episodeStep < self.args.tempThreshold)

            pi = self.mcts.getActionProb(canonicalBoard, temp=temp)

            if np.sum(pi) == 0: break

            #sym = self.game.getSymmetries(canonicalBoard, pi)
            #for b,p in sym:
            #    trainExamples.append([b, self.curPlayer, p, None])
            #self.game.print_board(canonicalBoard)

            action = np.random.choice(len(pi), p=pi)
            trainExamples.append([canonicalBoard, self.curPlayer, pi, None, valids, episodeStep])
            board, self.curPlayer = self.game.getNextState(board, self.curPlayer, action)

            r = self.game.getGameEnded(board, self.curPlayer)

            if r!=0:
                return [(x[0],x[2],r*x[1], x[4], x[5], episodeStep) for x in trainExamples]
        #return [(x[0],x[2],0) for x in trainExamples]
        print("the game's not ended")
        return []

    def learn(self):
        """
        Performs numIters iterations with numEps episodes of self-play in each
        iteration. After every iteration, it retrains neural network with
        examples in trainExamples (which has a maximium length of maxlenofQueue).
        It then pits the new neural network against the old one and accepts it
        only if it wins >= updateThreshold fraction of games.
        """

        for i in range(1, self.args.numIters+1):
            # bookkeeping
            print('------ITER ' + str(i) + '------')
            # examples of the iteration
            if not self.skipFirstSelfPlay or i>1:
                iterationTrainExamples = deque([], maxlen=self.args.maxlenOfQueue)

                eps_time = AverageMeter()
                bar = Bar('Self Play', max=self.args.numEps)
                end = time.time()

                for eps in range(self.args.numEps):
                    self.mcts = MCTS(self.game, self.nnet, self.args)   # reset search tree
                    iterationTrainExamples += self.executeEpisode()

                    # bookkeeping + plot progress
                    eps_time.update(time.time() - end)
                    end = time.time()
                    bar.suffix  = '({eps}/{maxeps}) Eps Time: {et:.3f}s | Total: {total:} | ETA: {eta:}'.format(eps=eps+1, maxeps=self.args.numEps, et=eps_time.avg,
                                                                                                               total=bar.elapsed_td, eta=bar.eta_td)
                    bar.next()
                bar.finish()

                # save the iteration examples to the history
                self.trainExamplesHistory.append(iterationTrainExamples)
                trainStats = [0,0,0]
                for res in iterationTrainExamples:
                    trainStats[res[2]] += 1
                print(trainStats)
            if len(self.trainExamplesHistory) > self.args.numItersForTrainExamplesHistory:
                print("len(trainExamplesHistory) =", len(self.trainExamplesHistory), " => remove the oldest trainExamples")
                self.trainExamplesHistory.pop(0)
            # backup history to a file
            # NB! the examples were collected using the model from the previous iteration, so (i-1)
            self.saveTrainExamples(i-1)

            # shuffle examlpes before training
            trainExamples = []
            for e in self.trainExamplesHistory:
                trainExamples.extend(e)
            shuffle(trainExamples)
            
            # training new network, keeping a copy of the old one
            self.nnet.save_checkpoint(folder=self.args.checkpoint, filename='temp.pth.tar')
            self.pnet.load_checkpoint(folder=self.args.checkpoint, filename='temp.pth.tar')
            pmcts = MCTS(self.game, self.pnet, self.args)
            
            self.nnet.train(trainExamples)
            nmcts = MCTS(self.game, self.nnet, self.args)

            print('PITTING AGAINST PREVIOUS VERSION')
            arena = Arena(lambda x: np.argmax(pmcts.getActionProb(x, temp=0)),
                          lambda x: np.argmax(nmcts.getActionProb(x, temp=0)), self.game)
            pwins, nwins, draws = arena.playGames(self.args.arenaCompare)

            print('NEW/PREV WINS : %d / %d ; DRAWS : %d' % (nwins, pwins, draws))
            if pwins+nwins > 0 and float(nwins)/(pwins+nwins) < self.args.updateThreshold:
                print('REJECTING NEW MODEL')
                self.nnet.load_checkpoint(folder=self.args.checkpoint, filename='temp.pth.tar')
            else:
                print('ACCEPTING NEW MODEL')
                self.nnet.save_checkpoint(folder=self.args.checkpoint, filename=self.getCheckpointFile(i))
                self.nnet.save_checkpoint(folder=self.args.checkpoint, filename='best.pth.tar')

    def getCheckpointFile(self, iteration):
        return 'checkpoint_' + str(iteration) + '.pth.tar'

    def saveTrainExamples(self, iteration):
        folder = self.args.checkpoint
        if not os.path.exists(folder):
            os.makedirs(folder)
        filename = os.path.join(folder, self.getCheckpointFile(iteration)+".examples")
        with open(filename, "wb+") as f:
            Pickler(f).dump(self.trainExamplesHistory)
        f.closed

    def loadTrainExamples(self):
        modelFile = os.path.join(self.args.load_folder_examples_file[0], self.args.load_folder_examples_file[1])
        examplesFile = modelFile+".examples"
        if not os.path.isfile(examplesFile):
            print(examplesFile)
            r = input("File with trainExamples not found. Continue? [y|n]")
            if r != "y":
                sys.exit()
        else:
            print("File with trainExamples found. Read it.")
            with open(examplesFile, "rb") as f:
                self.trainExamplesHistory = Unpickler(f).load()
            f.closed
            # examples based on the model were already collected (loaded)
            self.skipFirstSelfPlay = True