#!/usr/bin/env python3
import matplotlib.pyplot as p,numpy as n
x,y=n.meshgrid(n.linspace(-4,4,512),n.linspace(-4,4,512))
z=(1-x/2+x**4+y**3)*n.exp(-x**2-y**2)*(1-x/3-y**4)*(3-y+x**2)
z+=.5*n.sin(.8*x+.6*y)+.4*n.cos(.5*x-.7*y)+.3*n.sin(.6*x-.4*y)
p.contour(x,y,z,levels=n.linspace(z.min(),z.max(),25),cmap='terrain')
p.show()