import random class Location(object): def __init__(self, x, y): """x and y are floats""" self.x = x self.y = y def move(self, deltaX, deltaY): """deltaX and deltaY are floats""" return Location(self.x + deltaX, self.y + deltaY) def getX(self): return self.x def getY(self): return self.y def distFrom(self, other): ox = other.x oy = other.y xDist = self.x - ox yDist = self.y - oy return (xDist**2 + yDist**2)**0.5 def __str__(self): return '<' + str(self.x) + ', ' + str(self.y) + '>' class Field(object): def __init__(self): self.drunks = {} def addDrunk(self, drunk, loc): if drunk in self.drunks: raise ValueError('Duplicate drunk') else: self.drunks[drunk] = loc def moveDrunk(self, drunk): if not drunk in self.drunks: raise ValueError('Drunk not in field') xDist, yDist = drunk.takeStep() self.drunks[drunk] = self.drunks[drunk].move(xDist, yDist) def getLoc(self, drunk): if not drunk in self.drunks: raise ValueError('Drunk not in field') return self.drunks[drunk] class Drunk(object): def __init__(self, name): self.name = name def takeStep(self): stepChoices = [(0,1), (0,-1), (1, 0), (-1, 0)] return random.choice(stepChoices) def __str__(self): return 'This drunk is named ' + self.name def walk(f, d, numSteps): start = f.getLoc(d) for s in range(numSteps): f.moveDrunk(d) return(start.distFrom(f.getLoc(d))) def simWalks(numSteps, numTrials): homer = Drunk('Homer') origin = Location(0, 0) distances = [] for t in range(numTrials): f = Field() f.addDrunk(homer, origin) distances.append(walk(f, homer, numSteps)) return distances def drunkTest(numTrials): #for numSteps in [0, 1]: for numSteps in [10, 100, 1000, 10000, 100000]: distances = simWalks(numSteps, numTrials) print 'Random walk of ' + str(numSteps) + ' steps' print ' Mean =', sum(distances)/len(distances) print ' Max =', max(distances), 'Min =', min(distances) def rollDie(): """returns a random int between 1 and 6""" return random.choice([1,2,3,4,5,6]) def testRoll(n = 10): result = '' for i in range(n): result = result + str(rollDie()) print result import pylab ##pylab.plot([1,2,3,4], [1,2,3,4]) ##pylab.plot([1,4,2,3], [5,6,7,8]) ##pylab.show() ##pylab.figure(1) ##pylab.plot([1,2,3,4], [1,2,3,4]) ##pylab.figure(2) ##pylab.plot([1,4,2,3], [5,6,7,8]) ##pylab.savefig('firstSaved') ##pylab.figure(1) ##pylab.plot([5,6,7,10]) ##pylab.savefig('secondSaved') ##pylab.show() principal = 10000 #initial investment interestRate = 0.05 years = 20 values = [] for i in range(years + 1): values.append(principal) principal += principal*interestRate pylab.plot(values) pylab.title('5% Growth, Compounded Annually') pylab.xlabel('Years of Compounding') pylab.ylabel('Value of Principal (\$)') pylab.show()