def CreateNfg(dim):
"""
Create a new normal form game with the given dimensions
and assign outcomes at all contingencies
"""
nfg = gambit.NewTable(dim)
profile = gambit.PureStrategyProfile(nfg)
for cont in CrossProduct([
range(1,
nfg.GetPlayer(pl).NumStrategies() + 1)
for pl in range(1,
nfg.NumPlayers() + 1)
]):
map(
lambda pl: profile.SetStrategy(
nfg.GetPlayer(pl).GetStrategy(cont[pl - 1])),
range(1,
nfg.NumPlayers() + 1))
profile.SetOutcome(nfg.NewOutcome())
return nfg
def AsNfg(self):
game = gambit.NewTable([len(self.contribs) for i in xrange(self.N)])
# Label each strategy by its contribution
for (pl, player) in enumerate(game.Players()):
for (st, strategy) in enumerate(player.Strategies()):
strategy.SetLabel(str(self.contribs[st]))
for cont in gambit.StrategyIterator(gambit.StrategySupport(game)):
# Create and attach an outcome to this contingency
outcome = game.NewOutcome()
cont.SetOutcome(outcome)
# This is the vector of choices made in this contingency
choices = [
int(cont.GetStrategy(pl + 1).GetLabel())
for pl in xrange(self.N)
]
for pl in xrange(self.N):
outcome.SetPayoff(
pl + 1, self.Payoff(choices[pl],
sum(choices) - choices[pl]))
return game
# Function mapping own choice and choices of others into payoffs
def Payoff(alpha, omega, own, others):
# Cost share depends only on lower quantities and one's own
lower = [x for x in others if x <= own]
lower.sort()
lower.append(own)
payoff = gambit.Rational(omega) + gambit.Rational(alpha * own)
for k in xrange(1, len(lower) + 1):
payoff -= gambit.Rational(
Cost(Qsuper(lower, k)) - Cost(Qsuper(lower, k - 1)), N + 1 - k)
return payoff
game = gambit.NewTable([len(strats) for i in xrange(N)])
# Label each strategy
for pl in xrange(N):
player = game.GetPlayer(pl + 1)
for st in xrange(player.NumStrategies()):
strategy = player.GetStrategy(st + 1)
strategy.SetLabel(str(strats[st]))
for (i,
cont) in enumerate(gambit.StrategyIterator(gambit.StrategySupport(game))):
if i % 1000 == 0: sys.stderr.write("%d\n" % i)
# Create and attach an outcome to this contingency
outcome = game.NewOutcome()
cont.SetOutcome(outcome)
# This is the vector of choices made in this contingency
#
# A Python script to test the Gambit Python wrapper by building
# the minimum-unique-integer game
#
import gambit, sys
K = int(sys.argv[2])
N = int(sys.argv[1])
nfg = gambit.NewTable([K for i in range(N)])
# Pre-create outcomes. Outcome 'i' is the outcome where player 'i' wins.
for pl in xrange(1, nfg.NumPlayers() + 1):
outcome = nfg.NewOutcome()
outcome.SetLabel('%d wins' % pl)
outcome.SetPayoff(pl, "1")
for profile in gambit.StrategyIterator(gambit.StrategySupport(nfg)):
choices = [
profile.GetStrategy(pl).GetNumber()
for pl in range(1,
nfg.NumPlayers() + 1)
]
for ch in range(1, K + 1):
if len([x for x in choices if x == ch]) == 1:
# We have a winner
profile.SetOutcome(nfg.GetOutcome(choices.index(ch) + 1))
break
# If we don't have a winner, leave outcome null, payoffs zero