"""
Code fragment for plotting the posterior
for the coin-tossing example in module 1.5.2
"""

import scipy.stats

dist = scipy.stats.beta

plt.figure(figsize=(12, 12))
for idx, N in enumerate(trials):
    if idx == 0:
        plt.subplot(4,3, 2)
    else:
        plt.subplot(4,3, idx+3)
    y = data[idx]
    for (a_prior, b_prior), c in zip(beta_params, ('b', 'r', 'g')):
        p_theta_given_y = dist.pdf(x, a_prior + y, b_prior + N - y)
        plt.plot(x, p_theta_given_y, c)
        plt.fill_between(x, 0, p_theta_given_y, color=c, alpha=0.3)

    # plt.axvline(theta_real, ymax=0.3, color='k')
    plt.plot(0, 0, label="{:d} experiments\n{:d} heads".format(N, y), alpha=0)
    plt.xlim(0,1)
    plt.ylim(0,12)
    plt.xlabel(r'$\theta$') 
    plt.legend()
    plt.gca().axes.get_yaxis().set_visible(False)
plt.tight_layout()