import matplotlib.pyplot as plt

from metro1_data import tas, cum_probs

# Update matplotlib parameters.
params = {'text.usetex': True,
          'figure.dpi': 200,
          'font.size': 14,
          'font.serif': [],
          'font.sans-serif': [],
          'font.monospace': [],
          'axes.labelsize': 16,
          'axes.titlesize': 18,
          'axes.linewidth': .6,
          'legend.fontsize': 14,
          'xtick.labelsize': 12,
          'ytick.labelsize': 12,
          'font.family': 'serif'}
plt.rcParams.update(params)

plt.figure(figsize=(7, 5))

plt.step(tas, cum_probs, 'o-', color='blue', where='post')

idx = 3
epsilon = (cum_probs[idx] + cum_probs[idx+1]) / 2
ta_star = tas[idx+1]
plt.plot([tas[0], ta_star], [epsilon, epsilon],
         linestyle='dashed', color='black')
plt.annotate(r'$\epsilon$', (tas[0], epsilon), va='center', ha='right')

plt.xlabel('$ta$')
plt.ylabel('$F$')
plt.xlim(tas[0], tas[-1])
plt.ylim(bottom=0)
plt.tight_layout()
plt.show()