Matplotlib contour from xyz data: griddata invalid index

Question

I\'m trying to do a contour plot using matplotlib of a file with the following format:

x1 y1 z1

x2 y2 z2

etc

I can load it with numpy.loadtxt

Answer 1

ok, I finally found the solution to plot it. For those interested, here is the trick: use the griddata from Scipy with the 'nearest' method.

from scipy.interpolate import griddata
import numpy as np
import matplotlib.pyplot as plt
x=np.linspace(1.,10.,20)
y=np.linspace(1.,10.,20)
z=z = np.random.random(20)
xi=np.linspace(1.,10.,10)
yi=np.linspace(1.,10.,10)

X,Y= np.meshgrid(xi,yi)
Z = griddata((x, y), z, (X, Y),method='nearest')
plt.contourf(X,Y,Z)