# Constants defining the neuron's response curve
minact, rest, thresh, decay, maxact = -0.2, -0.1, 0.0, 0.1, 1.0
alpha, gamma, estr = 0.1, 0.1, 0.4
units = []
pools = []
unitbyname = {}
class Unit(object):
__slots__ = ['name', 'pool', 'extinp', 'activation', 'output', 'exciters', 'newact']
def __init__(self, name, pool):
self.name = name
self.pool = pool
self.reset()
self.exciters = []
unitbyname[name] = self
def reset(self):
self.setext(0.0)
self._setactivation()
def setext(self, weight=1.0):
self.extinp = weight
def _setactivation(self, val=rest):
self.activation = val
self.output = max(thresh, val)
def addexciter(self, aunit):
self.exciters.append(aunit)
def remove(self, aunit):
self.exciters.remove(aunit)
def computenewact(self):
ai = self.activation
plus = sum(exciter.output for exciter in self.exciters)
minus = self.pool.sum - self.output
netinput = alpha*plus - gamma*minus + estr*self.extinp
if netinput > 0:
ai = (maxact-ai)*netinput - decay*(ai-rest) + ai
else:
ai = (ai-minact)*netinput - decay*(ai-rest) + ai
self.newact = max(min(ai, maxact), minact)
def commitnewact(self):
self._setactivation(self.newact)
class Pool(object):
__slots__ = ['sum', 'members']
def __init__(self):
self.sum = 0.0
self.members = set()
def addmember(self, member):
self.members.add(member)
def updatesum(self):
self.sum = sum(member.output for member in self.members)
def display(self):
result = sorted(((unit.activation, unit.name) for unit in self.members), reverse=True)
for i, (act, unitbyname) in enumerate(result):
print '%s: %.2f\t' % (unitbyname, act),
if i % 4 == 3: print
print '\n'
def load(filename):
"""Load in a database and interpret it as a network
First column must be unique keys which define the instance units.
Each column is a pool (names, gangs, ages, etc).
Every row is mutually excitory.
"""
units[:] = []
pools[:] = []
for line in open(filename):
relatedunits = line.split()
if not len(relatedunits): continue
key = len(units)
for poolnum, name in enumerate(relatedunits):
if poolnum >= len(pools):
pools.append(Pool())
pool = pools[poolnum]
if name in unitbyname:
unit = unitbyname[name]
else:
unit = Unit(name, pool)
units.append(unit)
pool.addmember(unit)
if poolnum > 0:
units[key].addexciter(unit)
unit.addexciter(units[key])
def reset():
for unit in units:
unit.reset()
def depair(i, j):
unitbyname[i].remove(unitbyname[j])
unitbyname[j].remove(unitbyname[i])
def touch(itemstr, weight=1.0):
for name in itemstr.split():
unitbyname[name].setext(weight)
def run(times=100):
"""Run n-cycles and display result"""
for i in xrange(times):
for pool in pools:
pool.updatesum()
for unit in units:
unit.computenewact()
for unit in units:
unit.commitnewact()
print '-' * 20
for pool in pools:
pool.display()
if __name__ == '__main__' or 1:
load('jets.txt')
touch('Ken', weight=0.8)
run()
reset()
touch('Sharks 20 jh sing burglar')
run()
reset()
touch('Lance')
depair('Lance','burglar')
run()
SampleFile = """
Art Jets 40 jh sing pusher
Al Jets 30 jh mar burglar
Sam Jets 20 col sing bookie
Clyde Jets 40 jh sing bookie
Mike Jets 30 jh sing bookie
Jim Jets 20 jh div burglar
Greg Jets 20 hs mar pusher
John Jets 20 jh mar burglar
Doug Jets 30 hs sing bookie
Lance Jets 20 jh mar burglar
George Jets 20 jh div burglar
Pete Jets 20 hs sing bookie
Fred Jets 20 hs sing pusher
Gene Jets 20 col sing pusher
Ralph Jets 30 jh sing pusher
Phil Sharks 30 col mar pusher
Ike Sharks 30 jh sing bookie
Nick Sharks 30 hs sing pusher
Don Sharks 30 col mar burglar
Ned Sharks 30 col mar bookie
Karl Sharks 40 hs mar bookie
Ken Sharks 20 hs sing burglar
Earl Sharks 40 hs mar burglar
Rick Sharks 30 hs div burglar
Ol Sharks 30 col mar pusher
Neal Sharks 30 hs sing bookie
Dave Sharks 30 hs div pusher
"""
