# The Jets and the Sharks # Code developed in lab Wednesday, March 29, 2006 #---------------------------------------------------------------------- # global parameters of the model ALPHA = 0.4 # external input scale factor BETA = 0.1 # excitation scale factor GAMMA = 0.1 # inhibition scale factor MINIMUM = -0.2 # minimum allowable unit activation MAXIMUM = 1.0 # maximum allowable unit activation DECAY = 0.1 # activation decay factor RESTING = -0.1 # resting activation level of a unit #---------------------------------------------------------------------- class Unit: def __init__(self, label): self.label = label self.activation = RESTING self.externalInput = 0 self.connectionsIn = [] self.activationChange = 0 def __str__(self): return self.label def show(self): print "Label: %s" % self.label print "Activation: %.4f" % self.activation print "External input: %d" % self.externalInput print "Incoming connections:" for c in self.connectionsIn: print c def connectTo(self, otherUnit, strength): c = Connection(self, otherUnit, strength) otherUnit.connectionsIn.append(c) def computeActivationChange(self): # compute excitation and inhibition coming into this unit excitation = 0 inhibition = 0 for c in self.connectionsIn: v = c.fromUnit # only process positively activated units if v.activation > 0: if c.strength > 0: # excitatory connection excitation = excitation + v.activation * c.strength else: # inhibitory connection inhibition = inhibition + v.activation * c.strength # compute total incoming activation to this unit totalInput = ALPHA*self.externalInput + BETA*excitation + GAMMA*inhibition # scale the total input if totalInput > 0: scaledInput = (MAXIMUM - self.activation) * totalInput else: scaledInput = (self.activation - MINIMUM) * totalInput # compute activation change for this unit self.activationChange = scaledInput - DECAY*(self.activation - RESTING) def setActivation(self): self.activation = self.activation + self.activationChange # keep the unit's activation within bounds if self.activation > MAXIMUM: self.activation = MAXIMUM if self.activation < MINIMUM: self.activation = MINIMUM #---------------------------------------------------------------------- class Connection: def __init__(self, fromUnit, toUnit, strength): self.fromUnit = fromUnit self.toUnit = toUnit self.strength = strength def __str__(self): if self.strength > 0: sign = "+" else: sign = "-" return "%-10s--[%s]--> %s" % (self.fromUnit, sign, self.toUnit) #---------------------------------------------------------------------- def connectProperties(instanceUnit, propertyUnits): # create mutually excitatory connections between an instance unit # and all units in the propertyUnits list for p in propertyUnits: instanceUnit.connectTo(p, +1) for p in propertyUnits: p.connectTo(instanceUnit, +1) def connectInhibitory(units): # create mutually inhibitory connections between all pairs of # units within a group of units for u in units: for v in units: if u != v: u.connectTo(v, -1) def oneCycle(): # perform one complete activation update for u in allUnits: u.computeActivationChange() for u in allUnits: u.setActivation() jsnet.update() def run(n): # run the network for n time steps for i in range(n): oneCycle() def showAct(): # print out positively activated units for u in allUnits: if u.activation > 0: print "%-10s%.4f" % (u.label, u.activation) def clamp(unit): # turn on external input to a unit unit.externalInput = 1 print "Clamped %s" % unit.label jsnet.redraw() def unclamp(unit): # turn off external input to a unit unit.externalInput = 0 print "Unclamped %s" % unit.label jsnet.redraw() def reset(): # reset the network to its initial state for u in allUnits: u.activation = RESTING u.externalInput = 0 print "Network reset" jsnet.reset() #---------------------------------------------------------------------- if __name__ == '__main__': jets = Unit("Jets") sharks = Unit("Sharks") in20s = Unit("in20s") in30s = Unit("in30s") in40s = Unit("in40s") juniorhigh = Unit("J.H.") highschool = Unit("H.S.") college = Unit("College") single = Unit("Single") married = Unit("Married") divorced = Unit("Divorced") burglar = Unit("Burglar") bookie = Unit("Bookie") pusher = Unit("Pusher") nameArt = Unit("Art") nameAl = Unit("Al") nameSam = Unit("Sam") nameClyde = Unit("Clyde") nameMike = Unit("Mike") nameJim = Unit("Jim") nameGreg = Unit("Greg") nameJohn = Unit("John") nameDoug = Unit("Doug") nameLance = Unit("Lance") nameGeorge = Unit("George") namePete = Unit("Pete") nameFred = Unit("Fred") nameGene = Unit("Gene") nameRalph = Unit("Ralph") namePhil = Unit("Phil") nameIke = Unit("Ike") nameNick = Unit("Nick") nameDon = Unit("Don") nameNed = Unit("Ned") nameKarl = Unit("Karl") nameKen = Unit("Ken") nameEarl = Unit("Earl") nameRick = Unit("Rick") nameOl = Unit("Ol") nameNeal = Unit("Neal") nameDave = Unit("Dave") instArt = Unit("(art)") instAl = Unit("(al)") instSam = Unit("(sam)") instClyde = Unit("(clyde)") instMike = Unit("(mike)") instJim = Unit("(jim)") instGreg = Unit("(greg)") instJohn = Unit("(john)") instDoug = Unit("(doug)") instLance = Unit("(lance)") instGeorge = Unit("(george)") instPete = Unit("(pete)") instFred = Unit("(fred)") instGene = Unit("(gene)") instRalph = Unit("(ralph)") instPhil = Unit("(phil)") instIke = Unit("(ike)") instNick = Unit("(nick)") instDon = Unit("(don)") instNed = Unit("(ned)") instKarl = Unit("(karl)") instKen = Unit("(ken)") instEarl = Unit("(earl)") instRick = Unit("(rick)") instOl = Unit("(ol)") instNeal = Unit("(neal)") instDave = Unit("(dave)") gangUnits = [jets, sharks] ageUnits = [in20s, in30s, in40s] educationUnits = [juniorhigh, highschool, college] maritalUnits = [single, married, divorced] jobUnits = [pusher, burglar, bookie] nameUnits = [nameArt, nameAl, nameSam, nameClyde, nameMike, nameJim, nameGreg, nameJohn, nameDoug, nameLance, nameGeorge, namePete, nameFred, nameGene, nameRalph, namePhil, nameIke, nameNick, nameDon, nameNed, nameKarl, nameKen, nameEarl, nameRick, nameOl, nameNeal, nameDave] instUnits = [instArt, instAl, instSam, instClyde, instMike, instJim, instGreg, instJohn, instDoug, instLance, instGeorge, instPete, instFred, instGene, instRalph, instPhil, instIke, instNick, instDon, instNed, instKarl, instKen, instEarl, instRick, instOl, instNeal, instDave] allUnits = gangUnits + ageUnits + educationUnits + maritalUnits + jobUnits + \ nameUnits + instUnits connectProperties(instArt, [nameArt, jets, in40s, juniorhigh, single, pusher]) connectProperties(instAl, [nameAl, jets, in30s, juniorhigh, married, burglar]) connectProperties(instSam, [nameSam, jets, in20s, college, single, bookie]) connectProperties(instClyde, [nameClyde, jets, in40s, juniorhigh, single, bookie]) connectProperties(instMike, [nameMike, jets, in30s, juniorhigh, single, bookie]) connectProperties(instJim, [nameJim, jets, in20s, juniorhigh, divorced, burglar]) connectProperties(instGreg, [nameGreg, jets, in20s, highschool, married, pusher]) connectProperties(instJohn, [nameJohn, jets, in20s, juniorhigh, married, burglar]) connectProperties(instDoug, [nameDoug, jets, in30s, highschool, single, bookie]) connectProperties(instLance, [nameLance, jets, in20s, juniorhigh, married, burglar]) connectProperties(instGeorge, [nameGeorge, jets, in20s, juniorhigh, divorced, burglar]) connectProperties(instPete, [namePete, jets, in20s, highschool, single, bookie]) connectProperties(instFred, [nameFred, jets, in20s, highschool, single, pusher]) connectProperties(instGene, [nameGene, jets, in20s, college, single, pusher]) connectProperties(instRalph, [nameRalph, jets, in30s, juniorhigh, single, pusher]) connectProperties(instPhil, [namePhil, sharks, in30s, college, married, pusher]) connectProperties(instIke, [nameIke, sharks, in30s, juniorhigh, single, bookie]) connectProperties(instNick, [nameNick, sharks, in30s, highschool, single, pusher]) connectProperties(instDon, [nameDon, sharks, in30s, college, married, burglar]) connectProperties(instNed, [nameNed, sharks, in30s, college, married, bookie]) connectProperties(instKarl, [nameKarl, sharks, in40s, highschool, married, bookie]) connectProperties(instKen, [nameKen, sharks, in20s, highschool, single, burglar]) connectProperties(instEarl, [nameEarl, sharks, in40s, highschool, married, burglar]) connectProperties(instRick, [nameRick, sharks, in30s, highschool, divorced, burglar]) connectProperties(instOl, [nameOl, sharks, in30s, college, married, pusher]) connectProperties(instNeal, [nameNeal, sharks, in30s, highschool, single, bookie]) connectProperties(instDave, [nameDave, sharks, in30s, highschool, divorced, pusher]) connectInhibitory(gangUnits) connectInhibitory(ageUnits) connectInhibitory(educationUnits) connectInhibitory(maritalUnits) connectInhibitory(jobUnits) connectInhibitory(nameUnits) connectInhibitory(instUnits) from jsGraphics import JSNetwork jsnet = JSNetwork(allUnits)