plot2d.py

import matplotlib.pyplot as plt
import numpy as np

min = -5
max = 5
step = .1

width = (max-min)/step

fx0 = lambda x, y: abs(x) + abs(y)
fx1 = lambda x, y: x**2 + y**2
fx2 = lambda x, y: abs(x**3) + abs(y**3)

fxs = [
	lambda x, y: abs(x) + abs(y),
	lambda x, y: x**2 + y**2,
	lambda x, y: abs(x**3) + abs(y**3),
	lambda x, y: x**20 + y**20,
]

for fx in fxs:
	x,y = np.mgrid[min:max:((max-min)/step)*1j, min:max:((max-min)/step)*1j]
	z = fx(x,y)

	extent = [min, max, min, max]

	plt.imshow(z, extent=extent)
	plt.colorbar()
	plt.contour(z, levels=[1.0], colors=["black"], extent=extent)
	plt.show()