"""
Animation recipe 1.
This is the simplest approach, where we just show the 
animation as the program runs, and then it stops
without saving any files.
"""

import matplotlib.pyplot as plt
import numpy as np

def f(x, m, s):
    return (1.0/(np.sqrt(2*np.pi)*s))*np.exp(-0.5*((x-m)/s)**2)

m = 0; s_start = 2; s_stop = 0.2
s_values = np.linspace(s_start, s_stop, 30)
x = np.linspace(m - 3*s_start, m + 3*s_start, 1000)

# f er maks for x=m (mindre s gir større maksverdi)
max_f = f(m, m, s_stop)
y = f(x, m, s_stop)
lines = plt.plot(x,y) # Returnerer en liste med linje-objekter!

plt.axis([x[0], x[-1], -0.1, max_f])
plt.xlabel('x')
plt.ylabel('f')

for s in s_values:
    y = f(x, m, s)
    lines[0].set_ydata(y) # oppdater plottdata og tegn på nytt
    plt.draw()
    plt.pause(0.1)