#98 Making a movie of a plot

#98 Making a movie of a plot

Consider Gaussian bell function.

import matplotlib.pyplot as plt
import numpy as np
import os

os.chdir(r'D:\projects\wordpress\ex99') 
os.getcwd()

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, 50) #number of png files
x = np.linspace(m -3*s_start, m + 3*s_start, 1000)
# f is max for x=m (smaller s gives larger max value)
max_f = f(m, m, s_stop)
y = f(x,m,s_stop)
lines = plt.plot(x,y)
plt.axis([x[0], x[-1], -0.1, max_f])
plt.xlabel('x')
plt.ylabel('f')
frame_counter = 0
for s in s_values:
    y = f(x, m, s)
    lines[0].set_ydata(y) #update plot data and redraw
    plt.draw()
    plt.savefig(f'tmp_{frame_counter:03d}.png',dpi=300) #unique filename
    frame_counter += 1

Install programm ffmpeg for Windows and run the following command:

ffmpeg -f image2 -i D:/projects/wordpress/ex99/tmp_%03d.png movie.mpg