15_10.py

def flip(numFlips):
    """numFlips: 正の整数"""
    heads = 0
    for i in range(numFlips):
        if random.choice(('H', 'T')) == 'H':
            heads += 1
    return heads/float(numFlips)

def flipSim(numFlipsPerTrial, numTrials):
    fracHeads = []
    for i in range(numTrials):
        fracHeads.append(flip(numFlipsPerTrial))
    mean = sum(fracHeads)/len(fracHeads)
    sd = stdDev(fracHeads)
    return (fracHeads, mean, sd)

def labelPlot(numFlips, numTrials, mean, sd):
    pylab.title(str(numTrials) + ' trials of' + str(numFlips) + ' flips each')
    pylab.xlabel('Fraction of Heads')
    pylab.ylabel('Number of Trials')
    pylab.annotate('Mean = ' + str(round(mean, 4)) + '\nSD = ' + str(round(sd, 4)), size='x-large', xycoords = 'axes fraction', xy = (0.67, 0.5))

def makePlots(numFlips1, numFlips2, numTrials):
    val1, mean1, sd1 = flipSim(numFlips1, numTrials)
    pylab.hist(val1, bins=20)
    xmin,xmax = pylab.xlim()
    labelPlot(numFlips1, numTrials, mean1, sd1)
    pylab.figure()
    val2, mean2, sd2 = flipSim(numFlips2, numTrials)
    pylab.hist(val2)
    pylab.xlim(xmin, xmax)
    labelPlot(numFlips2, numTrials, mean2, sd2)
    pylab.show()

makePlots(100, 1000, 100000)