python - How to smooth matplotlib contour plot?

Question

I have numpy array with this shape: (33,10). When I plot contour I get ugly image like this:

while contour() doesn't seem to have any argument about smoothing or some sort of interpolation feature.

I somehow expected that tool which offers contour plot should offer smoothing too.
Is there straight forward way to do it in MPL?

Answer 1

As others have already pointed out, you need to interpolate your data.

There are a number of different ways to do this, but for starters, consider scipy.ndimage.zoom.

As a quick exmaple:

import numpy as np
import scipy.ndimage
import matplotlib.pyplot as plt

data = np.loadtxt('data.txt')

# Resample your data grid by a factor of 3 using cubic spline interpolation.
data = scipy.ndimage.zoom(data, 3)

plt.contour(data)
plt.show()