Interpolating data

interpolation.py

'''
Smoothing/Interpolation-example, based on
https://docs.scipy.org/doc/scipy-0.14.0/reference/tutorial/interpolate.html
'''
from __future__ import division
import numpy as np
from scipy.interpolate import interp1d
import matplotlib.pyplot as plt
import time

plt.ion()

for i in range(4, 15):
    plt.cla()
    x = np.linspace(0, 10, i)
    y = np.cos(-x ** 2 / 8)
    f = interp1d(x, y + 0.25 )
    f2 = interp1d(x, y + 0.5, kind='cubic')

    xnew = np.linspace(0, 10, 400)

    xx = np.linspace(0, 10, 100)
    yy = np.cos(-xx ** 2 / 8)

    plt.plot(x,y,'bo')
    plt.plot(xx,yy,'b')
    plt.plot(xnew,f(xnew),'r-')
    plt.plot(xnew, f2(xnew),'g--')

    plt.legend(['data points', 'data', 'shifted linear int',
        'shifted cubic int'], loc=3)
    plt.title(' '.join(['interpolating', str(i), 'points']))
    plt.ylim([-2,2])
    plt.draw()
    time.sleep(1)

plt.ioff()
plt.show()