Plot with tricontourf and tripcolor Python

#!/usr/bin/env python
import matplotlib.pyplot as plt
import matplotlib.tri as tri
import numpy as np
import math
from scipy.interpolate import griddata
data = np.genfromtxt('input.txt')
x = data[:,0]
y = data[:,1]
z = data[:,2]
f, ax = plt.subplots(1,2, sharex=True, sharey=True)
triaf=ax[0].tripcolor(x,y,z)
ax[0].plot(x,y, 'ko ')
contf=ax[1].tricontourf(x,y,z, 20) # choose 20 contour levels
ax[1].plot(x,y, 'ko ')
f.colorbar(triaf)
plt.show()