How to smooth date based data in matplotlib?

Question

I have a 2 lists, first with dates (datetime objects) and second with some values for these dates. When I create a simple plot:

plt.plot_date(x=dates, y=dur, fmt='r-')

I get a very ugly image like this.

How I can smooth this line? I think about extrapolation, but have not found a simple function for this. In Scipy there are very difficult tools for this, but I don't understand what I must add to my data for extrapolation.

Answer 1

You can make it smooth using sp.polyfit

Code:

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

# sampledata
x = np.arange(199)
r = np.random.rand(100)
y = np.convolve(r, r)

# plot sampledata
plt.plot(x, y, color='grey')

# smoothen sampledata using a 50 degree polynomial
p = sp.polyfit(x, y, deg=50)
y_ = sp.polyval(p, x)

# plot smoothened data
plt.plot(x, y_, color='r', linewidth=2)

plt.show()