import numpy as np
x = np.linspace(0,6,100)
y = np.sin(x)
z = np.cos(x)

import matplotlib.pyplot as plt
plt.plot(x,y,'r--',linewidth=3)
plt.plot(x,z,'k:',linewidth=2)
plt.legend(['y','z'])
plt.xlabel('x')
plt.ylabel('values')
plt.xlim([0, 3])
plt.ylim([-1.5, 1.5])
plt.savefig('myFigure.png')
plt.savefig('myFigure.eps')
plt.show()