def MakeNormalPlot(weights):
    """Generates a normal probability plot of birth weights.

    weights: sequence
    """
    mean, var = thinkbayes2.TrimmedMeanVar(weights, p=0.01)
    std = math.sqrt(var)

    xs = [-5, 5]
    xs, ys = thinkbayes2.FitLine(xs, mean, std)
    thinkplot.plot(xs, ys, color='0.8', label='model')

    xs, ys = thinkbayes2.NormalProbability(weights)
    thinkplot.plot(xs, ys, label='weights')
def MakeNormalModel(weights):
    """Plots a CDF with a Normal model.

    weights: sequence
    """
    cdf = thinkbayes2.Cdf(weights, label='weights')

    mean, var = thinkbayes2.TrimmedMeanVar(weights)
    std = math.sqrt(var)
    print('n, mean, std', len(weights), mean, std)

    xmin = mean - 4 * std
    xmax = mean + 4 * std

    xs, ps = thinkbayes2.RenderNormalCdf(mean, std, xmin, xmax)
    thinkplot.plot(xs, ps, label='model', linewidth=4, color='0.8')
    thinkplot.cdf(cdf)