正弦波を点で正負2つ表示

sin.py

#!/usr/bin/env python3

import matplotlib.pyplot as plt
import numpy as np
import matplotlib.animation as animation
from fractions import Fraction as fract
# from mpl_toolkits.mplot3d import Axes3D

fig = plt.figure(figsize=[16,9])

x = np.linspace(0, 2*np.pi, 1000)

def plot(data):
    plt.cla()
    plt.yticks(np.arange(-1, 1, step=0.05))
    plt.ylim(-1,1)
    for _cnt in range(100):
        alpha = 2*np.pi*0.1*data-fract(1,10)*_cnt
        y = np.sin(alpha)
        plt.scatter(_cnt, y)
        plt.scatter(_cnt, -y)

ani = animation.FuncAnimation(fig, plot, interval=10)

ani.save("test.gif", writer = 'imagemagick')
#plt.show()